Protocols & Lab Techniques
Guides
Holotype: Botanical Definition and Curation Guide
Holotype is the single physical specimen fixing a plant name under the ICN. Learn how herbaria curate, catalog, and preserve primary name-bearing types.
Inertial Confinement: Physics, Drivers & Fusion
Technical guide to inertial confinement fusion (ICF), detailing direct and indirect laser drivers, target ablation, Lawson criterion, and lab facilities.
Nanoscale: Definition, Range and Lab Standards
A guide to the nanoscale (1 to 100 nm), detailing ISO/TS 80004-1, FDA, and EPA standards, quantum effects, particle taxonomy, and lab safety protocols.
Fermi Gamma-ray Space Telescope Guide
Fermi Gamma-ray Space Telescope guide: technical specs for the LAT and GBM instruments, pair-conversion physics, and FSSC research data analysis workflows.
Radial Velocity: Principles, Methods and Standards
Radial velocity measures line-of-sight motion. Review IAU standards, Doppler spectrograph limits, exoplanet mass metrics, and repository pipelines.
Xpose: NONMEM Model Diagnostics and R Workflow Guide
Xpose is an open-source R package for NONMEM model diagnostics. Learn how to import run files and generate ggplot2-based goodness-of-fit plots for PopPK.
Allosteric Modulator: Mechanisms, Types, and Assays
A guide to allosteric modulators in pharmacology: PAM and NAM mechanisms, IUPHAR cooperativity factors, screening assays, and subtype selectivity.
Lipinski Rule of Five: Drug-Likeness Criteria
A guide to Lipinski’s Rule of Five for oral drug bioavailability: the four physicochemical cutoffs, screening workflows, Veber rules, and bRo5 exceptions.
Respiratory Quotient: Definition, Formulas, and RER
The respiratory quotient (RQ) measures cellular metabolic substrate use via VCO2 to VO2. Understand RQ vs RER and indirect calorimetry calculations.
Mine Rescue: Standards, Teams and Equipment
Mine rescue teams handle underground emergencies under MSHA 30 CFR 49, requiring 4-hour breathing apparatus, gas checks, and rigorous emergency drills.
Copper Smelting: Metallurgy, Furnaces & Stages
Copper smelting extracts pure copper from sulfide ores through roasting, furnace smelting, converting, and electrolytic refining under EPA emission limits.
Orthopedic Implants: Types, Materials and Rules
A technical guide to orthopedic implants, FDA 21 CFR Part 888 classifications, ASTM biomaterial standards, stress shielding, and hospital supply logistics.
Radiology Artificial Intelligence: Uses and Rules
A guide to radiology artificial intelligence covering FDA regulations, GMLP standards, clinical imaging workflows, and multisociety governance frameworks.
OpenVSP: Parametric Aircraft Geometry Guide
Learn how OpenVSP creates parametric 3D aircraft models, runs VSPAERO aerodynamic analyses, and exports meshes for aerospace research and CFD pipelines.
Solid Mechanics: Principles, Protocols & V&V
Engineering guide to solid mechanics: ASTM E8/E8M tensile testing, ASTM E1012 frame alignment, and ASME V&V 10 computational verification and validation.
LS-DYNA: Solvers, Keywords and Research Use
Explore LS-DYNA: explicit and implicit solvers, keyword deck structure, multiphysics coupling, material models, and computational research workflows.
Turbomachinery
Turbomachinery guide: Euler equations, flow types, ASME PTC 10/22 test codes, and ISO 20816 vibration severity zones for aerospace and mechanical research.
Solid Rocket Motor: Grain Design & Ballistics
Technical guide to solid rocket motors: Saint-Robert burn rates, chamber pressure equilibrium, propellant grain geometries, and test cell safety standards.
NASA CEA: Chemical Equilibrium Code Guide
NASA CEA calculates chemical equilibrium and theoretical rocket performance. Learn its Gibbs free energy solver, problem types, and modern Python workflows.
Thermal Interface Material: Types & ASTM D5470
Thermal interface material principles, ASTM D5470 test methods, NASA vacuum test data, bond line thickness physics, and comparative selection guidelines.
Hot-Wire Anemometry: Principles & Calibration
Hot-wire anemometry measures fluid velocity and turbulence via thermal sensors. Learn CTA principles, calibration protocols, King’s law, and probe selection.
CVXPY: Python Convex Optimization Modeling Guide
Technical guide to CVXPY for Python convex optimization: problem specification, disciplined convex programming rules, solver matching, and lab workflows.
Model Theory: Logic, Structures & Model vs Theory
A guide to model theory: syntax vs semantics, Tarskian truth, compactness, model vs theory comparisons, and applications in formal verification.
Ergodic Theory: Theorems and Dynamical Systems
An authoritative guide to ergodic theory: measure-preserving transformations, Birkhoff ergodic theorems, the ergodic hierarchy, and simulation implications.
Metal Injection Moulding: Process & Standards
Technical guide to metal injection moulding: feedstock compounding, debinding methods, sintering shrinkage, and ISO 22068 and ASTM B883 material standards.
Harmonic Analysis: Concepts, Transforms & Lab Uses
Understand harmonic analysis: principles, Fourier and wavelet transforms, MSC2020 classifications, and standardized IEC 61000-4-7 lab measurement practices.
Coastal Wetland: Definition, Types & Field Guide
Explore coastal wetlands: watershed definitions, Cowardin classification systems, tidal salinity zones, blue carbon storage, and field sampling protocols.
Maximum Sustainable Yield: Models, Reference Points, and Management
Learn how Maximum Sustainable Yield (MSY) defines harvest limits in fisheries science through surplus production models, B_MSY, and NOAA NS1 rules.
Demand Forecasting: Methods, Models, and Operational Application
Demand forecasting estimates future material needs using time series, causal models, and qualitative methods to optimize inventory, safety stock, and supply.
CSCMP: Supply Chain Management Standards Guide
An authoritative overview of the Council of Supply Chain Management Professionals (CSCMP), covering its SCM definitions, SCPro certification, and benchmarks.
FoodNet: Foodborne Active Surveillance Guide
FoodNet is CDC’s collaborative active surveillance network tracking major foodborne pathogens across 10 US sites to determine national burden and trends.
CITE-seq: Cellular Indexing of Transcriptomes
CITE-seq combines single-cell RNA sequencing with antibody-derived protein tags to measure transcriptomes and surface epitopes simultaneously in single cells.
Cell Host & Microbe: Scope, Fees and Guide
Cell Host & Microbe is a Cell Press journal covering host-pathogen biology. Learn its editorial scope, STAR Methods standards, and hybrid publishing models.
Global Initiative for Asthma: GINA Guidelines
The Global Initiative for Asthma (GINA) sets global clinical strategy, defining objective diagnostic criteria, the Assess-Adjust-Review loop, and AIR tracks.
Hybridoma
Hybridoma cells fuse B lymphocytes and myeloma cells to produce monoclonal antibodies. Explore HAT selection, culture protocols, cell banking, and QC.
Protein Subunit Vaccine: Design, Platforms & Use
Protein subunit vaccines use recombinant antigens (CHO, BEVS, yeast). Explore adjuvant mechanisms, regulatory CMC standards, and cold-chain supply decisions.
Vaccine Adjuvant: Types, Uses and Standards
A vaccine adjuvant enhances the immune response to an antigen. Explore FDA-approved adjuvant platforms, biological mechanisms, and lab handling standards.
Z Pulsed Power Facility: Architecture & Capabilities
A technical guide to Sandia National Laboratories’ Z Pulsed Power Facility, covering pulse compression architecture, Z-pinch mechanics, and HEDP research.
Ames National Laboratory: Scope & Research Guide
Ames National Laboratory is a DOE Office of Science national lab at Iowa State University focused on critical materials, rare earths, and materials discovery.
Wildlife Insights: Camera Trap Data Guide
A complete guide to Wildlife Insights: cloud architecture, deployment metadata schemas, AI species identification, and open biodiversity data sharing.
Fire Danger: Ratings, Indices & Field Protocols
Fire danger rates landscape fire potential using NFDRS indices. Understand adjective rating classes, fuel moisture models, and field station safety protocols.
FIREMON: Fire Effects Monitoring Guide
FIREMON provides standardized field methods and analysis tools to monitor post-fire ecological change, fuel loading, and burn severity across landscapes.
Forest Management: Principles and Planning
A complete reference on sustainable forest management, multi-use statutory planning under 36 CFR 219, FAO C&I pillars, and forest inventory field protocols.
Shelterwood System: Forestry Ecology and Silvicultural Management
An authoritative guide to the shelterwood silvicultural system, covering preparatory, seed, and removal cuts, regeneration ecology, and species suitability.
Forensic Document Examination: Methods & Tools
A practitioner guide to forensic document examination standards, handwriting comparison protocols, optical and chemical analysis, and lab evidence intake.
International Energy Conservation Code (IECC)
Guide to the International Energy Conservation Code (IECC): model energy rules, compliance pathways, DOE determinations, and research facility standards.
Ocean Energy: Principles, Types & IEC Standards
Comprehensive guide to ocean energy: wave, tidal, thermal, and osmotic power technologies, IEC TS 62600 standards, and testing laboratory protocols.
Ocean Thermal Energy Conversion: Formulas & Table
Ocean thermal energy conversion (OTEC) generates baseload power from thermal gradients. Explore thermodynamic formulas, lookup tables, and Python code.
Solar Irradiance: Components, Standards & Sensors
Solar irradiance measures instantaneous solar power per unit area in W/m2, encompassing direct, diffuse, and global components per ISO 9060.
Solar Power Tower: Systems, Receivers and Storage
Solar power tower systems concentrate sunlight via heliostat fields onto central receivers, driving high-temperature power cycles with thermal energy storage.
Surface Mount Technology: Standards & Methods
Surface mount technology (SMT) enables automated assembly of circuit boards without drilled lead holes. Explore manufacturing workflows and IPC standards.
librosa: Python Audio Signal Processing
A scientific guide to librosa, Python’s library for audio feature extraction, time-frequency analysis, and reproducible research signal processing.
Photonic Integrated Circuit: Guide and Platforms
A guide to photonic integrated circuits, comparing silicon photonics, InP, and Si3N4 platforms, EPDA simulation workflows, PDKs, and co-packaged optics.
SPIE Photonics West: Symposia, Papers, and Guide
A researcher’s guide to SPIE Photonics West: technical tracks, Proceedings of SPIE indexing, manuscript standards, and Moscone Center lab planning.
EMC Testing: Standards, Methods & Compliance
EMC testing evaluates emissions and immunity to ensure electronic lab and clinical devices operate without disruption under FCC Part 15 and IEC standards.
NISAR: NASA-ISRO Synthetic Aperture Radar Mission
NISAR is the joint NASA-ISRO radar satellite tracking Earth surface deformation, cryosphere dynamics, and ecosystems. Learn how L- and S-band SAR operates.
American Academy of Periodontology: AAP Guide
The American Academy of Periodontology (AAP) sets diagnostic staging and grading standards, guides periodontal therapy, and advances oral health research.
Kriegsspiel: Rules, Mechanics, and Wargaming
Explore the mechanics, adjudication rules, and defense research uses of Kriegsspiel, the 1824 Prussian system that established modern military wargaming.
Collaborative Combat Aircraft: MUM-T Architecture
Systems engineering guide to Collaborative Combat Aircraft (CCA), human-machine teaming imperatives, open architectures, and distributed C2 networks.
Phased Array Radar: Principles and Architectures
Phased array radar uses electronic beam steering across antenna arrays. Learn AESA vs PESA architectures, beamforming principles, and research applications.
Medable: Decentralized Clinical Trials Platform
Operational guide to Medable: modular decentralized clinical trial architecture, eConsent, eCOA, 21 CFR Part 11 compliance, and clinical site integration.
Cystatin C eGFR: Principles, Equations, and Clinical Accuracy
Understand cystatin C eGFR: learn how race-free CKD-EPI equations, tubular clearance, and KDIGO confirmatory criteria improve renal function estimation.
ARDS Berlin Definition: Criteria, Classification, and Clinical Scope
The ARDS Berlin definition defines diagnostic criteria, imaging standards, and 3 hypoxemia tiers using PaO2/FiO2 with a minimum PEEP of 5 cm H2O.
ICUC: Guide to the Urban Climate Conference
ICUC is the triennial International Conference on Urban Climate organized by the IAUC, convening global research on urban heat, microclimates, and design.
HEC-HMS: What It Models, Methods and Free Use Terms
What HEC-HMS models, the method options for loss, transform, baseflow and routing, and its no-charge terms for non-Corps users.
RESNA: Assistive Technology Standards & Roles
A guide to RESNA: ANSI assistive technology standards, ATP credentials, wheelchair testing methods, and clinical rehabilitation engineering practice.
3D-Printed Concrete: How It Works, Printability and Standards
3D-printed concrete explained: layer-by-layer extrusion, the printability triad, and what ISO/ASTM 52939 and ACI 564 do and do not cover.
AASHTO Green Book: What It Is and Which Edition Applies
What the AASHTO Green Book covers, how functional and context classes work, and which edition 23 CFR 625.4 names.
OpenSim: Musculoskeletal Modeling & Simulation
An overview of OpenSim for biomechanical modeling: computational architecture, inverse workflows, validation benchmarks, and movement simulation in research.
Neutron Activation Analysis (NAA): How It Works, Types, and Limits
How neutron activation analysis works: INAA, PGAA and delayed neutron counting compared, a sourced workflow, interference limits and questions for an NAA lab.
UniChem (EMBL-EBI): Chemical Identifier Cross-Reference Service
UniChem (EMBL-EBI) cross-references compound identifiers through Standard InChI. How UCIs and the API work, and a checklist for linking records.
Pittcon: The Analytical Chemistry Conference and Expo
What Pittcon is: the annual laboratory science conference and expo run by a Pittsburgh non-profit, its program parts, and how its proceeds fund outreach.
Xeno-canto: Wildlife Sound Repository Guide
A guide to Xeno-canto, covering its open-access bioacoustic archive, community dispute arbitration, Darwin Core schemas, and machine learning integration.
Continuous Stirred-Tank Reactor (CSTR): How It Works and When It Fits
How a continuous stirred-tank reactor works: ideal-CSTR assumptions, outlet-concentration formulas with worked values, and how lab reactors depart from them.
Undiagnosed Diseases Network (UDN): What It Is and How It Works
How the NIH-funded Undiagnosed Diseases Network is organised: clinical sites, sequencing cores, biorepository, and the application timeline.
Corrosion Protective Coatings: How They Work and Main Types
Corrosion protective coatings compared: barrier, sacrificial and inhibitive routes, binder trade-offs, a failure checklist and ISO 12944 categories.
Geroscience: Definition, the Geroscience Hypothesis and the Seven Pillars of Aging
Geroscience explained: how aging biology links to chronic disease, the 2014 seven pillars of aging, and how the framing changes lab study design.
Protein Science: What the Field Covers and How It Is Studied
What protein science covers, the four levels of protein structure, and how sequence, folding and PDB structure data connect to lab methods.
Myoelectric Prosthesis: How Muscle Signals Control It
How a myoelectric prosthesis turns muscle signals into movement, why lab accuracy overstates daily-life performance, and how FDA classifies powered arms.
Bumble Bee Watch: Protocols and Data Guide
Bumble Bee Watch protocols, expert taxonomic verification workflows, sensitive data policies, and integration into ecological and conservation research.
BEAST X (Bayesian Phylogenetics Software) Explained
BEAST X is open-source Bayesian phylogenetics software: what it does, its new model families, and a sourced pre-run checklist for labs.
NEBuilder: HiFi DNA Assembly and the Assembly Tool Explained
What NEBuilder means: the HiFi DNA Assembly Master Mix and the Assembly Tool, how overlap assembly works, and NEB’s design numbers in one table.
Designated Engineering Representative (DER): FAA Role Explained
FAA Designated Engineering Representative (DER) explained: appointment, company vs consultant types, Form 8110-3 limits and independence rules.
Airworthiness: Definition, Certificates and Duties
What airworthiness means, how FAA certificates are issued and kept valid, and who holds the continuing-airworthiness duty.
Flow Battery: What It Is and How Redox Flow Systems Work
A flow battery stores energy in electrolyte tanks pumped through a cell stack. Chemistries, limits and lab hazards, from DOE and ORNL sources.
Type Certificate Data Sheet (TCDS): Contents and How to Read One
What a type certificate data sheet (TCDS) is, its place in the type certificate under 14 CFR 21.41, and a section map and checklist for reading one.
KITTI Dataset: Contents, Sensors and Licence Terms
What the KITTI dataset contains, which sensors recorded it, what the raw release omits and what its licence and citation requests mean.
Qubit Fluorometer: How It Works and What It Measures
How a Qubit fluorometer quantifies DNA, RNA and protein, HS vs BR dsDNA ranges, and a checklist of manual-stated critical parameters.
Exclamation Mark Pictogram (GHS07): Meaning and Classes
Which OSHA hazard classes use the exclamation mark pictogram (GHS07), the rules that remove it from a label, and how to read it in the lab.
Reflux Apparatus: Setup, Condensers, and Protocol
A laboratory reflux apparatus maintains reactions at constant solvent boiling temperatures without fluid loss by condensing and returning vaporized solvent.
Heptane Boiling Point: 98.4 °C (371.5 K) and Lab Solvent Properties
Heptane boils at 98.4 °C (371.5 K) at 1 atm. Source values, freezing point, density, vapor pressure and what they mean for bench work.
Autoradiography: How It Works, Readout Options and Limits
Autoradiography images radioactive labels in a sample. Compare phosphor, real-time and whole-body readouts using published resolution and exposure figures.
Superantigens: Definition, Mechanism and Examples
Superantigens bypass antigen processing to activate many T cells at once. Definition, mechanism, antigen comparison table, examples and lab biosafety context.
Adenylation: Mechanisms, A-Tailing & Prep
A complete guide to adenylation in molecular biology: DNA ligase AMPylation mechanisms, 5′ pre-adenylated adapters, and 3′ A-tailing in NGS library prep.
Martin Agar: Principle, Selective Formula & Uses
Martin agar and Modified Thayer-Martin media use selective antimicrobials in chocolate agar to isolate Neisseria from mixed-flora clinical samples.
MEGA X: Molecular Evolutionary Genetics Analysis Software Explained
MEGA X is version 10 of the free MEGA phylogenetics software. See what it does, how MEGA-CC works, and how it differs from MEGA11 and MEGA 12.
Butanol Boiling Point: 117.6 °C and Other Lab Solvent Properties
1-Butanol boils at about 117.6 °C. A lab solvent reference card with density, vapor pressure, viscosity, pKa and polarity index from NIST and PubChem.
Single-Nuclei RNA-seq (snRNA-seq): How It Differs From Single-Cell
Single-nuclei RNA-seq (snRNA-seq) profiles isolated nuclei, suits frozen tissue. Compare genes detected and cell-type resolution with single-cell RNA-seq.
EF-1 Alpha Promoter (EF1a): What It Is and How It Compares With CMV
EF-1 alpha (EF1a) promoter explained: where it comes from, how it compares with CMV for silencing, and why different EF1a clones can differ up to 500-fold.
USP 825 Explained: Radiopharmaceutical Preparation, Compounding and Immediate Use
USP 825 explained: how it separates preparation, minor deviations and compounding of radiopharmaceuticals, and what the 1-hour immediate-use rule means.
Heteroduplexes: What They Are and How Labs Detect Them
Heteroduplexes are mismatched double-stranded DNA. See how they form, how gel mobility and enzyme cleavage detect them, and the homozygous blind spot.
Molecular Weight Cut-Off (MWCO): Meaning and Ratings
What MWCO means for dialysis and ultrafiltration membranes, why ratings differ between vendors, and what to record when comparing devices.
Affinity Constant (KD): Definition, Units and Reading Binding Affinity
What the affinity constant KD is, why lower KD means tighter binding, how it relates to kon and koff, and what occupancy it implies.
Ion Pairing in HPLC: Reagents, Mechanism and Lab Practice
Ion pairing in HPLC explained: how reagents retain charged analytes, a sourced reagent table, and equilibration and MS caveats.
Magnetic Separator: What It Is, Types and How It Works
What a magnetic separator is, how process and lab types work, and what each can and cannot remove, with manufacturer sources.
Romanowsky Stain: What It Is, How the Azure-Eosin Effect Works and How Wright and Giemsa Variants Differ
What a Romanowsky stain is, why purple chromatin appears, and a sourced WHO vs Wright-Giemsa kit comparison of pH, dilution and timing.
Reporter Gene: What It Is, Common Reporters and How They Are Read
What a reporter gene is, the three jobs it does, and a sourced comparison of lacZ, GFP, luciferase, GUS and CAT by how each is read.
Centrifuge Acceleration: Ramp Settings and Stop Times
What centrifuge acceleration means, how vendors set ramps, and how stop times differ by rotor for the same braking level.
Kjeldahl Method: How Nitrogen and Protein Are Determined
How the Kjeldahl method determines nitrogen and estimated protein: three steps, direct vs back titration, failure modes and limits.
Centrifuge Blood Samples: Settings by Tube Type and Safe Loading
How to centrifuge blood samples: manufacturer-stated RCF, time and rotor type by tube class, plus loading and safe-handling basics.
Phosphoproteomics: What It Is and How Phosphopeptides Are Enriched
What phosphoproteomics is, why phosphopeptides are enriched by IMAC or TiO2, and what to check when comparing results between labs.
CRISPOR: CRISPR Guide Design Tool, Scores and Limits
What CRISPOR does, how to read its three guide scores, which efficiency model suits U6 or T7 guides, and what published evidence says about its limits.
Optical Power Meter: Types, Sensors and Use
How optical and laser power meters work, which sensor suits which wavelength and power, and the specs and mistakes that affect a reading.
Sol-Gel: How a Sol Becomes a Gel (Xerogel vs Aerogel)
How sol-gel turns a sol into a gel, and why drying decides xerogel versus aerogel, with a sourced variable checklist.
Turbidity NTU Unit: Definition, Scale & Limits
Understand the turbidity NTU unit: optical measurement principles, EPA 180.1 vs ISO 7027 standards, calibration with formazin, and drinking water limits.
EBSD: Electron Backscatter Diffraction Guide
A technical guide to electron backscatter diffraction (EBSD), covering SEM beam geometry, Kikuchi pattern indexing, sample prep, and ASTM/ISO grain standards.
Implantable Neurostimulator: Systems and Standards
A technical overview of implantable neurostimulators, covering active hardware architecture, 21 CFR classification, ISO 14708-3 safety, and CT scan protocols.
Image Stitching in Microscopy: What It Is and How It Works
Image stitching joins overlapping microscope tiles into one image. See the three stages, how registration methods compare, and what to record.
Microdialysis: How It Works, Probes and Recovery
Microdialysis samples unbound, extracellular analytes through a low-flow perfused probe; recovery calibration decides how quantitative it is.
Zetasizer: What It Measures, Models and How It Compares
What the Malvern Panalytical Zetasizer measures, how Lab, Pro and Ultra differ, and how it compares with NanoSight and Mastersizer.
Hazmat Class 8: DOT Corrosive Materials, Packing Groups and Labels
What hazmat Class 8 (corrosive materials) means under 49 CFR: packing groups, the CORROSIVE label, and when a vehicle placard is required.
Gamma-H2AX (Gamma H2AX): The DNA Double-Strand Break Marker Explained
Gamma-H2AX (γ-H2AX) is Ser139-phosphorylated histone H2AX, a marker of DNA double-strand breaks. A sourced guide to reading foci: timing, dose, baseline, apoptosis.
GFAP Protein: Astrocyte Marker and Brain-Injury Biomarker
GFAP is the main astrocyte intermediate filament protein and a blood injury biomarker. See how the two uses differ and what the FDA record covers.
Planarian Regeneration: Neoblasts, Positional Genes and How Experiments Are Run
How planarian (planaria) regeneration works: neoblast stem cells, Wnt and notum polarity signals, and what RNAi and irradiation experiments show.
40 CFR Part 136: Guidelines for Water Analysis
40 CFR Part 136 establishes EPA-approved test procedures, preservation rules, and QA/QC requirements for Clean Water Act wastewater and ambient water testing.
What Is Electrospinning? Process, Parameters and Limitations
Electrospinning explained: how the process works, a sourced parameter-to-effect table, nanofiber examples, downsides and cost drivers.
Trimmomatic: Read Trimming Commands, Steps and Output Files
Trimmomatic trims adapters and low-quality bases from Illumina reads. Syntax for SE and PE, step order, ILLUMINACLIP modes and the four paired-end outputs.
QIIME 2: Architecture, Artifacts, and Workflow
Guide to QIIME 2 for microbiome analysis: learn .qza artifacts, .qzv visualizations, semantic typing, automated provenance tracking, and ASV workflows.
Lipofectamine 2000: Protocol Parameters and Comparison With 3000
Lipofectamine 2000 transfection reagent: vendor-reported protocol parameters, storage, where vendor guidance differs, and how it compares with 3000.
HSQC NMR: What It Is and How to Read It
What HSQC is, how its one-bond 1H-13C cross-peaks are read, how it compares with HMBC and DEPT, and which parameters a lab should record.
TMRE Dye Explained: Membrane Potential vs MitoSOX
TMRE reports mitochondrial membrane potential; MitoSOX is a different probe. Sourced controls, concentration limits and a comparison table.
ToF-SIMS (Time-of-Flight SIMS): Principle, Modes and Limits
ToF-SIMS explained: how time-of-flight secondary ion mass spectrometry analyses the top 1-2 nm, its three modes, sourced limits and ISO standards.
MEME Suite: Motif Discovery, Enrichment and Scanning Tools Explained
MEME Suite explained: which tool discovers, tests, scans or compares sequence motifs, with a task-to-tool table and input requirements.
Nephelometer: How It Measures Turbidity (NTU)
A nephelometer measures scattered light to estimate suspended particles; this page covers NTU, EPA 180.1 calibration, interferences and turbidimetry.
Myograph: What It Is, Wire vs Pressure Types and What It Measures
A myograph measures contraction of isolated vessels. Wire units record isometric force, pressure units record diameter; see readouts and selection questions.
Decanter Centrifuge: How It Works and Main Types
What a decanter centrifuge is, how bowl and scroll separate solids continuously, and how types and differential speed differ.
CRISPR Screening: Pooled vs Arrayed Screens and Libraries
How pooled and arrayed CRISPR screens work, positive vs negative selection, library types, and a pre-screen checklist, from Addgene and MAGeCK.
Ammonium Persulfate: SDS, Structure and Lab Uses
An operational guide to ammonium persulfate, covering chemical structure, SDS hazards, 10% stock stability, and role in polyacrylamide gel polymerization.
Tunicamycin: Mechanism of Action, Molecular Weight and Lab Handling
Tunicamycin blocks N-glycosylation via DPAGT1 and induces ER stress. Why its molecular weight varies by homologue, and a handling checklist.
Tetrahymena: Model Biology and Culture Guide
Guide to Tetrahymena biology, SPP culture media protocols, and life cycle dynamics, detailing nuclear dimorphism and ciliate model organism research.
CDCl3: Properties, NMR Use, and Lab Handling
A bench reference for CDCl3 in NMR spectroscopy: 1H and 13C residual solvent shifts, TMS calibration, decomposition chemistry, and storage best practices.
National Poultry Improvement Plan: Testing Guide
Guide to National Poultry Improvement Plan (NPIP) provisions, diagnostic testing standards, 9 CFR regulations, and biosecurity audit requirements.
Diagnostic Laboratory: Definition, Types and Oversight
Diagnostic laboratory defined: the CLIA legal definition, test complexity categories, and how human and animal-health labs differ.
Veterinary Pathology: Anatomic vs Clinical, Lab Services and Board Certification
Anatomic vs clinical veterinary pathology, which services AAVLD-accredited labs must offer on site, and how ACVP certification differs from accreditation.
Veterinary Diagnostics: Tests, Laboratories, Accreditation
Veterinary diagnostics explained: lab types, AAVLD accreditation, NAHLN levels and NVSL reference testing, with a checklist for judging a result.
SUDORS: The State Unintentional Drug Overdose Reporting System
What SUDORS is, which three record types feed it, how it grew since 2016, and what researchers should check before using it.
SEINet: Southwest Herbarium Data Portal Explained
SEINet is a Symbiota-powered portal for herbarium specimen records. See how it is organised, its sub-portals, and how to cite and reuse its data.
Direct Imaging of Exoplanets: How It Works
How exoplanet direct imaging works, which planets it can detect, and how to read imaging-discovered planets in catalogues.
OncoKB: Precision Oncology Knowledge Base, Annotator and API
OncoKB is MSK’s precision oncology knowledge base. Learn its evidence levels, API token tiers, Annotator scripts and what FDA recognition covers.
KATRIN Experiment: Karlsruhe Tritium Neutrino Mass Explained
KATRIN measures neutrino mass from tritium beta decay at KIT. Its 2025 result is an upper limit of 0.45 eV at 90% CL; what that means and what comes next.
SimBiology: MATLAB Software for QSP, PK/PD and PBPK
What SimBiology is, what it models (QSP, PK/PD, PBPK), and how NCA and NLME differ, from MathWorks documentation.
Para-Xylene (p-Xylene): Uses, Production, Hazards
Para-xylene is the xylene isomer made into terephthalic acid for PET; NIOSH exposure limits and freezing point versus o-xylene.
AFPM: American Fuel & Petrochemical Manufacturers Explained
AFPM is the American Fuel & Petrochemical Manufacturers trade association, formerly NPRA until 2012. What it does and the programs it lists.
Drilling Fluids: Types, Functions and Additives
What drilling fluid (mud) is, how EPA and OSHA classify its types, what each additive family does, and the EPA lab methods tied to it.
Riemannian Geometry: Core Concepts & Practice
A research-practice guide to Riemannian geometry: metric tensors, the Levi-Civita connection, curvature tensors, and applications in computational analysis.
Ankle-Foot Orthosis (AFO): Classification and Categories
Ankle-foot orthosis (AFO) explained: FDA Class I status, CMS prefabricated, custom fitted and custom fabricated definitions, and coverage criteria.
Ramsey Theory: Bounds, Principles, and Research
A comprehensive guide to Ramsey theory in combinatorics, covering exact Ramsey numbers, recent exponential bounds, and applications in computing research.
Clarion-Clipperton Zone: Deep-Sea Nodules and ISA Governance
What the Clarion-Clipperton Zone is, how ISA exploration contracts differ from its 13 protected areas, and how to cite ISA records correctly.
Mineral Resource: Definition, Categories and Reserve Differences
Mineral resource defined per the CRIRSCO template: Inferred, Indicated and Measured tests, conversion to reserves, and a checklist for reading a statement.
Mineral Deposit: Definition and How It Differs from Ore
USGS definitions of mineral occurrence, mineral deposit, ore deposit, resource and reserve, and how reporting codes fit in.
Open Pit Mining: What It Is and How Benches Work
Open pit mining explained: benches, pit wall angle, stripping ratio, why pits stop deepening, and the US slope stability rule.
Calculus of Variations: Principles & Methods
A technical guide to the calculus of variations: Euler-Lagrange equations, boundary conditions, variational principles, and computational implementations.
Topology Optimization: What It Is, How SIMP Works and Where It Fits
Topology optimization places material where a structure needs it. See how SIMP works, a pre-run checklist, and common misreadings of the result.
Neuromodulation Device: Types, Components and FDA Classification
Neuromodulation devices explained: implanted types with first FDA approval year, lead and generator layout, and Class II vs III under 21 CFR Part 882.
Supercritical CO2: What It Is, How It Works and Where It Is Used
What supercritical CO2 is, its NIST critical point, how density tuning and co-solvents work, reported extraction ranges and lab safety limits.
Unitary Plan Wind Tunnel (NASA Ames): What It Is and How It Works
The Unitary Plan Wind Tunnel at NASA Ames: three test sections on one shared drive, what each does, and which source to cite for sizes, Mach range and dates.
Turing Patterns: Reaction-Diffusion Mechanism and Evidence
How Turing patterns arise from reaction and diffusion, where the mechanism is contested, and a five-point evidence checklist.
Powder Metallurgy: Process, Methods and Standards
A technical guide to powder metallurgy: the press-and-sinter sequence, ASTM and ISO standards, MPIF material grades, and lab powder characterization.
Magnetic Materials: Types, Specs and Lab Testing
A practitioner guide to magnetic materials: IEC 60404-1 classification, soft vs hard specs, VSM calibration via NIST SRM 772a, and lab safety protocols.
Integrated Multi-Trophic Aquaculture: IMTA
A guide to integrated multi-trophic aquaculture (IMTA), covering circular nutrient recycling, species balance, operational siting, and coastal biofiltration.
Work Sampling: Method, Formula and Lab Workflow
Work sampling is a statistical work measurement method using random instantaneous observations to determine the proportion of time spent on activities.
Memory T Cells: TCM, TEM, TRM and Marker Definitions
Memory T cell subsets compared by CD45RA, CCR7, CD69 and CD103, with a gating checklist and the blood-versus-tissue sampling limit.
CROI: Conference on Retroviruses and Opportunistic Infections
CROI explained: who runs it, how abstracts are reviewed, and the prior-publication, preprint and copyright rules to check before submitting.
Friction Stir Welding: Principles and Standards
A guide to friction stir welding (FSW): solid-state principles, tool kinematics, ISO 25239 and AWS D17.3 standards, and joint testing in research labs.
Nowcasting in Infectious Disease Surveillance: Reporting Delays Explained
Nowcasting estimates current disease trends from incomplete recent data. Learn reporting triangles, delay types and when nowcasts can mislead.
Secretory IgA (SIgA): Structure, Function and Measurement
Secretory IgA is the dimeric mucosal antibody built from IgA, J chain and secretory component; see its structure, subclasses and saliva measurement.
National Radio Astronomy Observatory (NRAO): What It Is and How Access Works
What the National Radio Astronomy Observatory is, who funds and operates it, and how competitive observing time works.
Frederick National Laboratory for Cancer Research Explained
FNLCR is an NCI-sponsored FFRDC in Frederick, Maryland, run by a contractor. Its structure, programs and facilities explained.
Innate Lymphoid Cells (ILCs): Types, Markers and Lab Relevance
What innate lymphoid cells are, how ILC1, ILC2 and ILC3 differ, and why mouse and human markers and tissue sampling matter at the bench.
Camera Trap: How It Works, Survey Design and Research Data Standards
How camera traps record wildlife, what survey effort INBO reports, and how CTMS and Camtrap DP structure the data.
Hypersonic Glide Vehicles: Systems & Testing
A technical guide to hypersonic glide vehicles: aerothermodynamic testing, boost-glide trajectory dynamics, thermal protection, and defense evaluation.
Over-the-Horizon Radar: Principles and Design
A technical guide to over-the-horizon radar: skywave vs. surface wave propagation, FMCW bistatic antenna arrays, Bragg clutter, and operational sensing.
TTB COLAs Online: Apply vs Search the Public COLA Registry
Apply in COLAs Online, search in the Public COLA Registry: what each TTB system does and what a registry record does not show.
SRTR: Scientific Registry of Transplant Recipients
A comprehensive reference on the Scientific Registry of Transplant Recipients (SRTR), covering its data linkages, risk-adjusted metrics, and research access.
Preventive Controls Qualified Individual (PCQI): Definition and Duties
What a preventive controls qualified individual (PCQI) is under 21 CFR 117, the eight tasks 117.180 assigns, training or experience routes, and records.
Continuous Emission Monitoring (CEMS): What It Measures and How It Is Checked
What a continuous emission monitoring system (CEMS) measures, how it differs from COMS and PEMS, and how Part 75 QA checks keep its data valid.
Wafer-Level Packaging: Fan-In vs Fan-Out and WLCSP Assembly
What wafer-level packaging is, how fan-in and fan-out differ, TI’s published WLCSP board-assembly limits, and the named causes of fan-out warpage.
Advanced Test Reactor (ATR): What It Is and How Researchers Use It
The Advanced Test Reactor at INL: sourced specifications, how its core runs simultaneous experiments, and how outside researchers apply for access.
GIDEP: Government-Industry Data Exchange Program Explained
What GIDEP is, who runs it, its document types and the FAR 52.246-26 screening and 60-day reporting duties.
Hydrogen Embrittlement: What It Is and How It Happens
Hydrogen embrittlement explained: affected metals, four sourced mechanisms compared, and DOE findings on hydrogen in steel pipelines.
Surviving Sepsis Campaign Guidelines: Protocol
Explore Surviving Sepsis Campaign guidelines: evidence-based recommendations, initial resuscitation bundles, diagnostic lab workflows, and post-ICU recovery.
Tin Whiskers: What They Are, Why They Cause Short Circuits and How They Are Controlled
Tin whiskers are conductive tin filaments that grow from plated surfaces and cause shorts. NASA failure modes, mitigation and IEC 62483 explained.
Electromagnetic Interference (EMI): Definition, Sources and Lab Impact
Electromagnetic interference (EMI) defined using FDA EMC guidance and FCC rules, with a vocabulary cross-walk and a facility checklist for labs and clinics.
What Is PLECS? Power Electronics Simulation Software
PLECS is Plexim’s power electronics simulation software. See what Standalone, Blockset, Coder and RT Box do and how a model is built.
FaceBase: The NIDCR Craniofacial Data Repository
What FaceBase is, how the consortium differs from the repository, and how deposit fits NIH data management planning.
GHG Protocol: Laboratory Implementation Guide
A guide to applying the GHG Protocol in laboratories: setting organizational boundaries, calculating Scope 1-3 emissions, and avoiding reporting pitfalls.
Climate Resilience: Definition, IPCC Wording and Steps to Resilience
Climate resilience per the IPCC AR6 glossary, versus adaptation and mitigation, with the U.S. Steps to Resilience sequence.
Recycled Asphalt Pavement (RAP): Uses and Lab Limits
What recycled asphalt pavement is, where it is used, and what FHWA says changes in binder and mix design as RAP content rises.
Data Acquisition System (DAQ): Components, Types and Lab Use
A data acquisition system (DAQ) links sensors, hardware and software. Learn its parts, architectures, and the sampling and resolution settings to record.
Mouse Metabolic Phenotyping Centers (MMPC): NIDDK Consortium Explained
The NIDDK-funded Mouse Metabolic Phenotyping Centers (MMPC): who runs them, what live-mouse tests they offer, and how data ownership works.
Human Microbiome Project (HMP): Aims, Phases and Findings
What the Human Microbiome Project was, how its two phases differ, what the 2012 and 2019 papers established, and what to check before reusing its data.
CAZy: The Carbohydrate-Active Enzymes Database Explained
CAZy classifies carbohydrate-active enzymes into GH, GT, PL, CE, AA and CBM families. Learn how to read a family ID and what CAZy can and cannot tell you.
Agent-Based Model (ABM): Definition, Components and ODD Checklist
What an agent-based model is, its three components, the software used, and the seven ODD elements to check when reading or documenting an ABM.
DeepLabCut: Markerless Pose Estimation Explained
DeepLabCut explained: what markerless pose estimation is, its four-stage workflow, SuperAnimal model terms and what a lab should record.
Optical Tweezers: How They Work and What Labs Use Them For
How optical tweezers trap beads with focused laser light, what labs use them for, and the wavelength and bead choices that matter.
Mathematical Biology: Definition, Methods and Funding
Mathematical biology uses models to study living systems. Definition, model families, NSF and NIGMS funding routes, and how it differs from systems biology.
LPSN: List of Prokaryotic Names with Standing in Nomenclature
LPSN is the DSMZ-hosted database of valid prokaryote names. Learn to read its typography, check a name’s status and cite it.
TreeBASE: What the Phylogenetic Repository Holds and How to Submit
TreeBASE is a repository of published phylogenetic trees and matrices. Submission checklist, private-until-published policy and citation by URI.
Movebank: Animal Tracking Data Platform and Repository
Movebank is a free animal tracking data platform; its separate Data Repository publishes reviewed, DOI-bearing datasets. Differences and a DMP checklist.
Pumped Storage: How It Works, Open-Loop vs Closed-Loop
Pumped storage hydropower explained with US DOE sources: the two-reservoir cycle, open-loop vs closed-loop, and what GW vs GWh means for grid storage.
AUVSI: What the Uncrewed Systems Association Is and Does
AUVSI is the nonprofit uncrewed systems association behind XPONENTIAL and Green UAS. What it is, what it is not, and what its labels mean for research buyers.
Aircraft Noise: How It Is Certified, Measured and Managed
ICAO noise certification chapters (Ch 2 to Ch 16), how DNL exposure differs from certification, and the 14 CFR Part 150 land-use line.
Lithium-Sulfur Battery: How It Works and Why It Fades
How a lithium-sulfur battery works, why 2600 Wh/kg is theoretical, and which failure modes hit the cathode, anode and separator.
Drive Cycle: Meaning, Types and Dynamometer Use
A drive cycle is a standardized speed-time trace for dynamometer tests, and also a driving pattern for OBD readiness. EPA and WLTC schedules compared.
No-Till: Definition, Criteria and How It Differs from Conservation Tillage
No-till defined by the NRCS standard: in-row disturbance only, residue kept, STIR cap, and how it differs from FAO conservation agriculture.
Vehicle Emissions: Pollutants, Standards and How They Are Measured
Vehicle emissions explained from EPA sources: regulated pollutants, the 2020 NOx, VOC and PM shares, and the dynamometer drive schedules used to test them.
OSHA 29 CFR Part 1910: General Industry Standards and the Subparts Labs Use
OSHA 29 CFR Part 1910 explained: the subparts A to Z, where the lab standard 1910.1450 sits, and direct answers on lighting and qualified persons.
Meso Scale Discovery (MSD): How the ECL Multiplex Immunoassay Works
How Meso Scale Discovery (MSD) ECL multiplex immunoassays work, with MSD vs ELISA validation data, limits in mouse samples, and ownership history.
Ultracentrifugation: Principles, Rotors and Uses
A guide to ultracentrifugation: preparative and analytical systems, rotor clearing factors, and density gradient separation protocols for lab researchers.
Thioglycolate Medium: Uses, Growth & Preparation
Thioglycolate medium cultures aerobic and anaerobic bacteria along a redox gradient. Learn FTM formulation, oxygen zoning, and USP sterility test protocols.
Bacteriological Water Testing: Standard Methods
Explore bacteriological water testing methods, standard protocols from EPA and WHO, indicator organisms, and analytical quality controls for water safety.
What Is a Gloss Meter? Principle, Geometries (20/60/85) and Use
A gloss meter measures specular gloss in gloss units (GU). Learn how to pick 20, 60 or 85 degrees, calibrate, sample and avoid common errors.
What Is a Hapten? Definition, Carriers and Conjugation
A hapten is a small molecule that binds antibodies but cannot trigger them alone. See the definition, haptenization meaning, carriers and a design checklist.
Stem Cell Differentiation: Potency, Evidence and How Labs Confirm It
How stem cell differentiation is shown at the bench: ISSCR evidence standards, marker pitfalls and what to report.
Basics of Laboratory Work: Skills, Safety and Records
What “basics of laboratory” means: technique (WHO manual) versus the plan, training and records every lab needs (OSHA 1910.1450), by source.
PrimerBank: Harvard’s PCR Primer Database Explained
What PrimerBank (the Harvard/MGH PCR primer database) covers, how to search it, what its 82.6% validation figure means, and related primer databases.
Tissue Engineering: Definition, Components and FDA-Listed Examples
Tissue engineering explained: definition, the cells-scaffold-signals triad, three approach types and FDA-listed examples.
MCF-10A Cells: Origin, Culture Spec and 3D Acini
MCF-10A is a non-tumorigenic human breast epithelial line (ATCC CRL-10317). Origin, ATCC culture spec, 3D acini use and what to record.
27F and 1492R Primers: Sequences, Amplicon, Limits
27F and 1492R amplify nearly the full 16S rRNA gene. Sequences, the ~1,400 bp amplicon, 27F-I vs 27F-II results and limits, from cited studies.
CAG Promoter (CAGGS): What It Is, Where It Came From and How Labs Use It
The CAG promoter combines a CMV enhancer with chicken beta-actin; learn its 1991 origin, the CAGGS naming and a sourced ES-cell comparison.
scFv Antibody (Single-Chain Variable Fragment): Structure and Uses
An scFv joins an antibody’s VH and VL domains with a flexible linker into one 25-30 kDa chain with no Fc. Formats and CAR-T uses.
TCR Sequencing (TCR-seq): Bulk vs Single-Cell Methods
TCR-seq reads rearranged α and β chain genes to identify T cell clones. Compare bulk and single-cell methods, DNA vs RNA input, and outputs.
Raji Cells: Burkitt Lymphoma B-Cell Line (ATCC CCL-86)
Raji cells explained: an EBV-positive Burkitt lymphoma B-cell line (ATCC CCL-86), with culture facts, genetics and a bank-identifier cross-walk.
18S Primer: qPCR Reference Gene vs 18S Amplicon Sequencing
18S primers serve two jobs: an RT-qPCR reference gene and eukaryote amplicon sequencing. Compare priming, caveats and published primer examples.
What Is Chelex? Chelex 100 Resin and DNA Extraction
What Chelex 100 resin is, what it removes, and the sourced limits of Chelex DNA extraction for PCR, with grades and mesh sizes tabulated.
Atom Transfer Radical Polymerization: Bench Guide
Guide to atom transfer radical polymerization (ATRP): catalytic redox mechanisms, initiator selection, reaction kinetics, and copper catalyst removal.
Cell Surface Marker: CD Names, Panels and Controls
What a cell surface marker is, how CD names are assigned, why panels (the ISCT MSC criteria) define cells, and which flow cytometry controls matter.
ChIP (Chromatin Immunoprecipitation): Principle, qPCR and Controls
ChIP explained: what chromatin immunoprecipitation measures, how ChIP-qPCR percent input differs from fold enrichment, and what IgG controls prove.
Cy5 Excitation and Emission: 650/670 nm, with Cy3, FITC and DAPI
Cy5 is excited near 650 nm and emits near 670 nm. One sourced table compares Cy3, FITC and DAPI, with laser-line match and why vendor values differ.
Myokine: Definition, Key Examples and How They Are Measured
A myokine is a peptide or protein released by skeletal muscle. Definition, examples, myostatin, exercise findings and an assay checklist for lab staff.
Oligomycin: ATP Synthase Inhibitor and Seahorse Use
Oligomycin inhibits mitochondrial ATP synthase. Mechanism, oligomycin A molecular weight, Seahorse assay role and what to check.
MEGAHIT Metagenome Assembler: What It Does and How to Run It
What the MEGAHIT metagenome assembler does, how its succinct de Bruijn graph works, the documented run options, and a checklist for reproducible runs.
Codon Optimization: What It Is and How It Works
Codon optimization recodes a gene with synonymous codons for a host. Definition, four design metrics, tool divergence and common misconceptions.
In Vitro Transcription: How Cell-Free RNA Synthesis Works
How in vitro transcription synthesizes RNA from a DNA template: T7 promoter classes, template quality, and the byproducts that need clean-up.
Tissue Microarray (TMA): What It Is and How It Is Used
Tissue microarray (TMA) explained: how cores from many cases share one block, manual vs automated building, and core-loss planning.
Micro-CT: Principles, Scanners and Lab Guide
A comprehensive laboratory guide to micro-CT (micro computed tomography) principles, scanner types, spatial resolution, and equipment procurement costs.
Microreactor (Chemical): Continuous-Flow Reactors Explained
Chemical microreactors are continuous-flow reactors with sub-millimetre channels. Sourced advantages, clogging and scale-up limits, and the nuclear homonym.
Hemp Production: Federal Rules From Field to Lab Test
How US hemp production is regulated: total THC, sampling agents, DEA-registered labs, and the 0.3%, 1.0% and three-strike thresholds.
Foldit: What the Protein Folding Game Is and How Researchers Use It
Foldit is a protein-folding puzzle game run by university labs. See what published studies show players contributed and how such work is credited.
Symbiota: Biodiversity Collections Portal Software Explained
Symbiota is GPL-2.0 open-source software for biodiversity collection portals; what it does by role and how it relates to GBIF and iDigBio.
Phytosanitary Certificate: What It Attests (ISPM 12)
A phytosanitary certificate attests that plant consignments meet import requirements. ISPM 12 issuer rules, model layout, re-export and replacement.
Deep Water Culture (DWC) Hydroponics: How It Works and What to Monitor
Deep water culture (DWC) grows plants with roots in aerated nutrient solution. Compare what two extension sources say about aeration, pH, EC and monitoring.
CD45: Pan-Leukocyte Marker, Isoforms and What Positive Means
CD45 (PTPRC) marks nucleated hematopoietic cells. Names, isoforms (RA, RO, B220) and what CD45 positive or negative means.
Boiling Stones (Boiling Chips): Purpose, Use and Limits
Boiling stones, boiling chips and anti-bumping granules explained: purpose, when to add them, why not under vacuum, and when to stir instead.
Takara Protein Ladder: CLEARLY Stained vs Unstained Compared
Takara’s CLEARLY protein ladders compared from the datasheets: unstained 3453A as a size standard, stained 3454A for migration and transfer checks.
CUT&RUN Chromatin Profiling: What It Is and How It Differs From ChIP-seq and ATAC-seq
CUT&RUN chromatin profiling explained: how it works, how it compares with ChIP-seq and ATAC-seq, and what to decide before running it.
Blasticidin: Mechanism, Resistance Genes (BSD, bsr) and Selection Concentrations
Blasticidin S selection: how it works, BSD vs bsr resistance genes, E. coli, yeast and mammalian starting concentrations, kill-curve design and storage.
QuantStudio Real-Time PCR Systems: Models, QuantStudio 5 Specs and Use
QuantStudio systems explained: the model family, QuantStudio 3 vs 5 values from Thermo Fisher sources, and a pre-run checklist for labs.
Cryogenic Sample Storage: -80 °C vs Vapor-Phase Nitrogen
Cryogenic sample storage explained: -80 °C vs vapor-phase liquid nitrogen, aliquoting, freeze-thaw, frozen blood and protein storage, from NCI guidance.
Morpholino: What It Is, How It Works and How to Validate It
What a morpholino is, how translation and splice blocking work, and which controls (mispair, second oligo, rescue, mutant) actually show specificity.
DMSO Boiling Point and Physical Properties: Lab Solvent Reference
DMSO boils at about 189 °C at 760 mmHg and freezes near 18.5 °C; compare multi-source density, vapor pressure, viscosity and pKa values.
Covaris Focused-Ultrasonicators (AFA) vs Bioruptor
Covaris AFA vs Bioruptor: how each shears DNA, with a sourced comparison of stated specs, plus a checklist for core-facility users.
USGS National Water Information System (NWIS): Data Types and the 2027 API Change
USGS National Water Information System data types, and how the legacy WaterServices shutdown on February 22, 2027 maps to the new Water Data APIs.
IQ-TREE: Maximum-Likelihood Phylogenetics Software Explained
IQ-TREE infers maximum-likelihood phylogenetic trees. Commands, output files, how to read UFBoot, SH-aLRT and concordance factors, and version differences.
ColabFold: What It Is and How It Differs from AlphaFold2
ColabFold pairs MMseqs2 search with AlphaFold2 models. See its three entry points, how it differs from the AlphaFold2 notebook, and what to expect.
Transformation Efficiencies: Formula, Units (cfu/µg) and Worked Examples
How to calculate transformation efficiency in cfu/µg, with two worked examples, why ligations give fewer colonies, and a no-colonies checklist.
Cell Painting: What the Assay Stains and Measures
Cell Painting stains eight cell components with six dyes and measures ~1,500 features per cell. Dye table, v3 changes and limitations.
Puromycin: Mechanism, Resistance Gene and Kill Curve
Puromycin explained: how it halts translation, the N-acetyltransferase resistance enzyme, and how a kill curve sets selection concentration.
Flammable Liquid Category 3: Flash Point, Label and Storage (OSHA/GHS)
OSHA flammable liquid Category 3 means a 23-60 C flash point, a Warning label and a 60-gallon cabinet limit. Compared with Categories 1, 2 and 4.
CyTOF (Mass Cytometry): How It Works vs Flow Cytometry
CyTOF is mass cytometry: metal-isotope antibody tags read by time-of-flight mass analysis. How it works, and how it differs from fluorescence flow cytometry.
alamarBlue Assay: What It Measures and How It Works
The alamar blue assay is a resazurin-based cell viability readout. See what it measures, the manufacturer’s read settings and how it compares.
Chloroform Density: 1.48 g/mL, Plus Boiling Point and Other Properties
Chloroform density is about 1.48 g/cm3, with sourced boiling point, molar mass, melting point, vapor pressure and viscosity from NIST and PubChem.
Golden Gate Assembly: How Type IIS One-Pot Cloning Works (MoClo, GoldenBraid)
Golden Gate assembly joins DNA parts in one tube with a Type IIS enzyme and ligase. Learn the design rules, MoClo and GoldenBraid standards, and limits.
Pyrosequencing: How It Works, Uses and vs Sanger
How pyrosequencing works, the four enzymes behind the light signal, methylation and SNP uses, and where Sanger or NGS fit better.
K2 EDTA Tubes (K2EDTA): What the Lavender Top Contains and Why Fill Volume Matters
K2 EDTA tubes explained: how the additive prevents clotting, FDA-recorded amounts per tube size, and what published work says about underfilling.
OD600: What It Measures and Why It Is Not a Cell Count
OD600 measures culture turbidity at 600 nm. Why converting to cells/mL needs calibration, with a sourced comparison of microsphere, LUDOX and CFU methods.
SYPRO Ruby and SYPRO Orange Protein Gel Stains: What They Are and When to Use Them
SYPRO Ruby and SYPRO Orange explained: sensitivity, supply format, imaging needs, a sourced Ruby vs Orange table and a pre-staining checklist.
Wistar Rats: Origin, Outbred Stock and Related Strains
Wistar rats are an outbred albino lab rat stock from the early 1900s. See how Wistar differs from Wistar Han, Kyoto, Sprague Dawley and Lewis.
Iba1 (AIF1): Microglia Marker, What It Labels and Its Limits
Iba1 (AIF1) labels microglia broadly but cannot show activation direction or separate microglia from infiltrating macrophages. Names, limits, pairing.
What Is a Sand Bath? Lab Heating Bath Types and Safe Use
A sand bath is a lab heating bath. Compare hotplate and fluidized types, with one worked spec example and sourced safety basics.
JASPAR: Transcription Factor Binding Profile Database Explained
JASPAR is an open-access database of curated transcription factor binding profiles. See its collections, access routes and how to cite the release.
Iodoacetamide: Cysteine Alkylation in Proteomics, Hazards and Alternatives
Iodoacetamide caps reduced cysteines in proteomics (carbamidomethyl, +57.021464 Da). Compare alternatives and review its GHS hazard classification.
Qualitative RT-PCR: How a Positive or Negative Call Is Made
Qualitative RT-PCR reports detected or not detected. See how run controls and Ct cutoffs decide positive, negative, inconclusive or invalid calls.
FastQC: What It Reports, Thresholds and How to Read It
FastQC checks one sequence file with 12 modules and flags pass, warn or fail. See the exact thresholds and how it differs from MultiQC and fastp.
Dynamic Mechanical Analyzer (DMA): What It Is and Standards
What a dynamic mechanical analyzer measures, the ASTM D4065 operating limits, test-mode standards, and why DMA Tg values depend on the method used.
Oil Immersion Lens: How It Works, Immersion Oil Types and Refractive Index
How an oil immersion objective works, the refractive index of immersion oil by wavelength, and Type A versus Type B viscosity from datasheets.
CellTiter-Glo Assay: How the Luminescent Viability Readout Works
How the CellTiter-Glo ATP luminescence viability assay works, how its variants differ, and what the readout cannot tell you.
Radioactivity Calculator: Ci, Bq, cpm, dpm and Decay Correction
Convert Ci, Bq and dpm, turn cpm into dpm with counting efficiency, and decay-correct lab nuclides using a sourced half-life table and worked examples.
Neurite: Definition, Outgrowth and How It Is Measured
A neurite is a developing neuron projection. Learn how it differs from axons and dendrites and how outgrowth is measured by length, count and branching.
Xylene Boiling Point: o-, m- and p-Xylene Properties for the Lab
Xylene boils at 138 to 144 °C by isomer, yet flashes at 25 to 30 °C. Side-by-side o-, m-, p-xylene properties and what they mean at the bench.
Tetrahydrofuran Boiling Point: 66 °C (339 K) Datasheet
Tetrahydrofuran boils at about 66 °C (339 K, 151 °F); melting point -108.4 °C; density, vapor pressure, pKa and bench implications by source.
MDCK Cells: Madin-Darby Canine Kidney Line, Sublines and Uses
What MDCK means, how MDCK and MDCK-II differ, ATCC culture conditions and why clone type matters for influenza and permeability work.
ZFNs (Zinc Finger Nucleases): How They Work vs TALENs and CRISPR
How ZFNs (zinc finger nucleases) work, how TALENs differ, and why CRISPR/Cas is easier to target, with a sourced comparison table.
Trichrome Stain: Masson’s Trichrome Principle, Colours and Uses
Trichrome stain explained: Masson’s trichrome for collagen in tissue versus the stool trichrome for protozoa, with a colour cross-walk from UNC and CDC.
DMF Boiling Point and Physical Properties: Lab Solvent Reference
DMF boils at 153 °C (152.8 °C CRC). Sourced datasheet: vacuum boiling points, density, vapour pressure, flash point, pKa and DMSO comparison.
What Are Sterile Urine Cups? Container Requirements for Urine Collection
A sterile urine cup is a lidded, leak-proof container used for urine culture. What two laboratory policies say about container type, volume and transport.
Coculture (Co-culture) in Cell Biology: Direct vs Indirect Systems
Coculture grows two or more cell types together to study their interaction. Compare direct and indirect designs, with sourced limits of 2D culture.
Pentane Boiling Point: 36 °C (309.2 K), Values by Source
Pentane boils at about 36 °C (309.2 K). Values by source for boiling and melting point, density and vapor pressure, and what they mean at the bench.
IMPC: International Mouse Phenotyping Consortium Explained
IMPC (International Mouse Phenotyping Consortium) is an open catalogue of knockout mouse phenotypes. How the data are made, accessed and used.
Public Health Emergency: Definition, US Section 319 Declarations and WHO PHEIC
How a US section 319 public health emergency differs from a WHO PHEIC: who declares each, how long it lasts, and where preparedness fits.
Z-Stack in Microscopy: What It Is, Step Size and Flattening in ImageJ
Z-stack in microscopy: what it is, how to choose z-step size for deconvolution, and how to flatten a stack with ImageJ Z Project.
BODIPY Dyes: Colors, 493/503, C11 and Staining Uses
BODIPY dye variants explained: color and spectra of FL, 493/503 and 581/591 (C11), what each reports, and what BODIPY staining does and does not show.
kDa to g/mol: Conversion, Formula and Worked Examples
1 kDa = 1,000 Da = 1,000 g/mol. How to convert kDa, Da and g/mol both ways, plus nmol to µg, with worked examples and common pitfalls.
FPbase: Fluorescent Protein Database, Spectra Viewer and How to Cite
FPbase explained: what the fluorescent protein database holds, which tool answers which question, API basics and a citation checklist.
SnapGene Viewer: Free Mode, What It Does and Does Not Do
SnapGene Viewer is now the free mode of SnapGene since version 8.0. A sourced checklist of what it does and what needs the unrestricted version.
PMSF (Phenylmethylsulfonyl Fluoride): What It Inhibits, Stability and Stock Solution
PMSF facts for lab staff: molecular weight, aqueous half-life at pH 7-8, 100 mM stock solvent and working concentration, and hazards.
Coulter Counter: How the Coulter Principle Works
A Coulter counter counts and sizes particles by the electrical pulse each makes in a constricted aperture. Principle, 1948-1958 history, limits checklist.
Hazmat Class 3: DOT Flammable and Combustible Liquids Explained
DOT Hazard Class 3 flammable and combustible liquids: 60 °C flash-point rule, packing groups, UN numbers, placards and USPS mailing limits.
Actinomycin D: Mechanism, Uses and Lab Handling
Actinomycin D (dactinomycin) binds DNA and blocks RNA synthesis. Mechanism, clinical versus research use, mRNA-chase caveats and cytotoxic handling.
CD11b (ITGAM, Mac-1): What the Marker Identifies
CD11b (ITGAM, Mac-1) explained: which cells express it, how it differs from CD11c, and whether NK cells carry it.
What Is Perturb-seq? Single-Cell CRISPR Screening Explained
Perturb-seq pairs pooled CRISPR screens with single-cell RNA-seq. Compare it with CROP-seq and review measured detection limits.
Ki-67: Proliferation Marker, IHC Clones and Scoring
What Ki67 labels, how it is scored by IHC, which clones and preanalytic steps matter, and why there is no universal cutoff.
Gravity Filtration: Setup, Fluted Paper and Hot Filtration
Gravity filtration setup, fluted paper, hot filtration for recrystallization, and a gravity vs vacuum selection table with troubleshooting.
mCherry: Red Fluorescent Protein Spectra and Properties
mCherry excitation and emission (587/610 nm), size, maturation and half-life, compared with tdTomato and mScarlet in one sourced table.
A549 Cells: Lung Adenocarcinoma Line, KRAS Status and Culture Facts
A549 is an established lung adenocarcinoma line (ATCC CCL-185), not primary or small cell, with homozygous KRAS G12S. Culture facts and a reporting checklist.
Neoantigens: What They Are and How Labs Identify Them
Neoantigens are tumour-specific mutated epitopes. How labs find them with paired sequencing, RNA-seq and HLA typing, and how they differ from TAAs.
Absorbance vs Optical Density (OD): Meaning, Formula and Readings
Absorbance and optical density explained: the formula, when OD equals absorbance, how to measure absorptivity, and what high or negative readings mean.
TRIzol RNA Extraction: How the Method Works and Key Parameters
TRIzol RNA extraction explained: what the reagent does, how aqueous, interphase and organic layers separate, and per-1 mL volumes, spins and yields.
Housekeeping Genes: Definition, Examples and qPCR Use
What housekeeping genes are, how they differ from constitutive genes, and what recent analyses say about using GAPDH and others as qPCR controls.
Phage Display: M13 Libraries, Biopanning and Applications
Phage display explained: M13 coat proteins, phagemid vs phage vector, naive vs immunized libraries and the biopanning cycle.
mRNA Capping: How the 5′ Cap Is Added and How Labs Cap Synthetic mRNA
How mRNA is capped, how it differs from splicing and polyadenylation, and how enzymatic and co-transcriptional capping routes for synthetic mRNA compare.
Alexa Fluor 647: Spectra, Colour and Cy5 Comparison
Alexa Fluor 647 spectra and colour next to Alexa 488, 555 and 594, and how Alexa dyes compare with Cy3 and Cy5.
What Is an RNA Extraction Kit? Contents, Formats and Sizes
RNA extraction kit explained: what is in the box, four kit formats, RNeasy size tiers by input and elution volume, and how purity and integrity are checked.
Gene Knockout: Methods, Models and Validation
A research guide to gene knockout mechanisms, CRISPR-Cas9 and Cre-lox models, multi-tier validation protocols, and genetic compensation troubleshooting.
India Ink Stain: Negative Capsule Staining for Cryptococcus
How the India ink negative stain reveals capsules in Cryptococcus, why it is only presumptive, and what the four meanings of the phrase are.
C57BL/6 Mouse: Substrains (6J vs 6N), Uses and Reporting
C57BL/6 is a family of inbred mouse substrains. Learn how 6J and 6N differ, what the names mean and what to report in methods and animal protocols.
NOESY: What It Is and How to Read It
NOESY is a 2D NMR experiment mapping through-space proximity; compare with COSY and ROESY, choose by molecular size, and read cross peaks.
Zeta Potential: Meaning, Units and How It Is Measured
Zeta potential explained: what it means, why it is reported in mV, how electrophoretic light scattering measures it, and what to report with the value.
Triethylamine Density: Lab Solvent Datasheet
Triethylamine density is 0.726 g/mL. Reference boiling point, vapor pressure, pKa, polarity, and safety data for extraction, rotovap, and HPLC workflows.
Neuraminidase: What It Is, What It Does in Influenza, and Which Drugs Block It
What neuraminidase does in influenza, how it differs from hemagglutinin, and why baloxavir is not a neuraminidase inhibitor.
Ames Assay: Bacterial Reverse Mutation Test Explained
The Ames assay counts revertant bacterial colonies, with and without S9, to flag mutagens. Strains, controls and a report checklist, per FDA and OECD 471.
Buffer Solution: What It Is, How It Resists pH Change and How to Choose One
A buffer solution resists pH change. See the Henderson-Hasselbalch check, a sourced pKa table of lab buffers and a checklist for choosing one.
Base Editing: Principles, Deaminase Architectures, and Window Selection
A technical guide to CRISPR base editing, detailing cytosine and adenine deaminases, editing windows, bystander mutations, and prime editing comparisons.
Medaka (Oryzias latipes): Model Fish Guide
Medaka (Oryzias latipes) as a lab model fish: inbred strains, DMY sex determination, stock centres, sourced figures and a strain-sourcing checklist.
Kozak Sequence: Consensus, Key Positions and Kozak vs Shine-Dalgarno
The Kozak sequence is the eukaryotic start-codon context: purine at -3, G at +4. Consensus, position table, and Kozak vs Shine-Dalgarno.
PROTAC: How Degraders Work, Hook Effect and FDA Status
How PROTAC degraders work, why the hook effect matters, how they differ from molecular glues, and their FDA status.
Total Petroleum Hydrocarbons (TPH): GRO, DRO and ORO Test Methods
TPH explained for lab staff: GRO, DRO and ORO fractions, EPA 8015D and TX1005 carbon ranges, and a checklist for reading a TPH result.
Electrometer: What It Is, How It Works and How It Differs From a Multimeter
Electrometer explained: four functions, how it differs from a multimeter or picoammeter, stated limits and a checklist of low-level error sources.
Single-Cell RNA Sequencing (scRNA-seq): Workflow from Capture to Count Matrix
How single-cell RNA sequencing works, from cell capture and barcoding to count matrix, with a capture-format comparison and QC checklist.
ÄKTA Chromatography Systems: What They Are and How the Range Differs
What ÄKTA chromatography systems are, and how ÄKTA start and pure differ in flow, pressure, weight and cold-room fit, from Cytiva datasheets.
Tissue Culture: What It Is, How It Works and Lab Setup
Tissue culture explained: stages, media, a lab equipment checklist, how long it takes and why it is not a home method, from IFAS and USDA-ARS sources.
Tris-HCl Buffer: pKa, pH Range, Temperature Shift and Preparation
Tris-HCl buffer: pKa, buffering range, temperature shift, 50 mM preparation logic and what to record.
Multi-Omics: Definition, Data Layers and Integration
What multi omics means, which data layers it combines, how integration works, and what to settle before a multi-omics study.
Light Sheet Microscopy: Principles & Lab Guide
A guide to light sheet microscopy: optical principles, SPIM versus oblique plane systems, Gaussian versus Bessel beams, and core lab operational workflows.
Coomassie Blue: Dye Structure, Staining Protocols, and Principles
A complete guide to Coomassie Blue staining for protein gel electrophoresis, comparing R-250 and G-250 dye formulations, protocols, and downstream workflows.
Dichloromethane Density: 1.3255 g/mL at 20 °C and Other Solvent Properties
Dichloromethane (DCM) density is about 1.33 g/mL at 20 °C. Sourced boiling point, vapor pressure and water solubility, and what they mean at the bench.
sgRNA Design: How to Choose a CRISPR Guide RNA
How to design an sgRNA for CRISPR-Cas9: spacer, PAM, seed region, on- and off-target scoring, and off-target mitigation options.
EcoR1 (EcoRI) Restriction Enzyme: Site, Cut and Buffer Activity
EcoRI (EcoR1) recognises GAATTC and leaves 5′ AATT overhangs. Enzyme facts, buffer activity and star-activity risks in one reference.
Custom Peptide Synthesis: Methods, Purity Grades, and an Ordering Checklist
Custom peptide synthesis explained: how peptides are built, what purity grades mean, which modifications exist, and a spec checklist for ordering.
Isotyping: What Antibody Isotyping Is and How It Is Done
What antibody isotyping is, how kits identify the isotype, why labs do it, and how it differs from an isotype control in flow cytometry.
Phosphate Buffer: Preparation, pKa & Lab Recipes
A practical guide to phosphate buffer preparation, Sørensen and potassium recipes, pKa values, temperature shifts, and essential lab troubleshooting.
Urea Molecular Weight: 60.06 g/mol, Solubility and Stock Preparation
Urea (CH4N2O) has a molecular weight of 60.0553 g/mol. Mass for 8 M, sourced solubility, and stock solution storage for research buffers.
Axolotl Regeneration: How the Blastema Rebuilds a Limb
How axolotl limb regeneration works: wound epidermis, blastema, positional memory, the 32 Gb genome, and how labs obtain animals from the AGSC.
Biolistic (Gene Gun): How Particle Bombardment Works
Biolistic delivery fires DNA-coated gold or tungsten particles into cells with helium. Compare handheld and vacuum gene guns and gold versus tungsten.
Sandwich ELISA Assay: Principle, What It Detects and When It Fits
Sandwich ELISA assay explained: how capture and detection antibodies trap an analyte, what it can detect, and a datasheet checklist.
Ellipsometer: What It Measures and How It Works
An ellipsometer measures polarization change (Ψ, Δ) to model film thickness and optical constants. Includes a checklist for trusting a fit.
Cyclohexane Boiling Point: 80.7 °C (353.9 K), Values by Source and Bench Meaning
Cyclohexane boils at 80.7 °C (353.9 K). Values by source, Antoine vapor pressure, density, freezing point and what they mean at the bench.
Circular Dichroism (CD) Spectroscopy: Principle, Setup and Limits
Circular dichroism explained: principle, CD vs ORD, instrumentation, far-UV buffer rules, a pre-run checklist and the limits of secondary-structure fits.
Nissl Stain: What It Shows and Cresyl Violet Explained
Nissl stain explained: what Nissl bodies indicate, cresyl violet vs Nissl, Nissl vs Golgi, and sourced limits such as soma-size bias.
TSA Plate (Tryptic Soy Agar): Formats, Composition and Uses
What a TSA plate is: tryptic soy agar composition, 100 and 150 mm formats, environmental-monitoring use, and FDA product code JSG.
Dendritic Spines: Structure, Types and How They Are Quantified
Dendritic spines: where they sit, spine types, density and turnover, and how Golgi, dye and two-photon methods differ when counting them.
Beta-Actin (ACTB): Size, Function and Western Blot Use
Beta-actin (ACTB) is a 375-residue, ~42 kDa cytoskeletal protein. Gene and protein names, function, and when it fails as a western blot loading control.
Necroptosis: RIPK3-MLKL Pathway, Markers and Assays
Necroptosis is caspase-independent regulated cell death driven by RIPK3 and MLKL. See the pathway and which assay readouts are specific.
CD68 Marker: What Cells Express It and How It Differs From CD163
CD68 is a lysosomal macrophage marker that is not macrophage-specific. See which cells express it and how it differs from CD163.
NSG Mice: Genetics, Research Uses, and Lab Care
Comprehensive reference on NSG mice: NOD scid gamma genetics, humanization and PDX applications, strain comparisons, and barrier husbandry standards.
GMS Stain: Principle, Controls, and Results by Organism
What a GMS stain detects, how it works, which controls and fixes apply, and what it shows for Candida, Cryptococcus, Aspergillus and Pneumocystis.
What Is Synthego? CRISPR Supplier Explained
Synthego explained: its CRISPR catalog, the 2024 EditCo and 2025 Perceptive Advisors transactions, and what research-use versus GMP tiers mean.
TCLP: Toxicity Characteristic Leaching Procedure (EPA Method 1311) Explained
TCLP is EPA Method 1311, the leaching test behind RCRA toxicity D-codes. Steps, the eight metal limits, and how liquids are handled.
Cycloheximide: Mechanism, Solubility and Safe Handling
What cycloheximide is, how it blocks eukaryotic translation, how sources compare on solubility, and why its GHS hazard class varies by supplier.
Biological Assay: Principles, Types, and Potency
A biological assay quantifies the potency or biological activity of a substance using living cells or tissues, governed by USP and FDA regulations.
Fecal Coliform: Definition, Testing Methods and Indicator Use
What fecal coliform means, how EPA Method 1680 defines and counts it, and how it differs from total coliform, E. coli and enterococci.
Cross Linker (Crosslinker): What It Is, Types, and How to Choose One
What a cross linker is, how reactive groups and spacer arms differ, which amino acids cross-link, and a checklist for choosing a reagent.
Pyroptosis: Gasdermin Pathway and How It Differs From Apoptosis
Pyroptosis is gasdermin-mediated inflammatory cell death. See the pathway, how it differs from apoptosis and necroptosis, and which assays separate them.
Abasic Site (AP Site) in DNA: Formation, Repair, Effects
An abasic (AP) site is a DNA position missing its base. How it forms, why it stalls polymerases, and which enzymes repair it.
PEGylation: Definition, PEG Structure and Naming (PEG 2000)
PEGylation defined: PEG structure, what PEG 2000 means, PEG 400 vs 6000, PEG-lipids in LNPs and characterization methods.
Mouse Embryonic Fibroblast (MEF) Cells: Feeder Use, Passage Limits and Inactivation
What MEF cells are, how feeder layers use them, usable passages, mitomycin C versus irradiation, and what to check when sourcing, from cited sources.
Nicking Endonuclease: What It Cuts, How It Is Made, and Where It Is Used
What a nicking endonuclease cuts, how Nt./Nb. names work, how nickers are made, and where labs use them in amplification and cloning.
Diffusion Cell: Franz Cell Apparatus and Diffusion in Cells Explained
What a diffusion cell is: Franz, static and flow-through designs, sink-condition checks, and simple versus facilitated diffusion in cells.
Lipaemic (Lipemic) Specimens: Causes, Interference and Handling
What a lipaemic (lipemic) specimen is, why lipemia has no universal normal range, which analytes it distorts, and how removal methods compare.
MRC-5 Cell Line: Human Diploid Lung Fibroblasts
What MRC-5 cells are, where they came from, their population-doubling limit, how they are obtained and their role as a vaccine substrate.
Chinese Hamster Ovary (CHO) Cells: Lines, Selection Systems and Uses
What CHO cells are, how CHO cell lines such as CHO-K1, DXB11 and DG44 differ, and how DHFR and GS selection compare.
Luciferin: What It Is and How D-Luciferin Is Used
Luciferin is the substrate luciferase oxidizes to make light. See how D-luciferin is prepared for cells, lysates and imaging, and what one vendor specifies.
Ferroptosis: Mechanism, Markers and Assays
Ferroptosis explained for researchers: GPX4 and FSP1 defences, inducers and rescue agents, and a checklist of lipid peroxidation assay readouts.
Fc Domain of an Antibody: Structure, Fab vs Fc and Function
What the Fc domain (Fc fragment, Fc portion) of an antibody is, how it differs from Fab and F(ab’)2, and IgG mass in kDa.
ES Cells (Embryonic Stem Cells): What They Are and How Labs Use Them
ES cells explained as a lab reagent: mouse ES cell culture (LIF, 2i), gene targeting, and an oversight checklist for human ES cell work.
What Is Incucyte? Live-Cell Analysis Systems Explained
Incucyte explained: how in-incubator live-cell imaging works, S3, SX5, SX1 and CX3 compared from the Sartorius datasheet, and a lab planning checklist.
Whole Genome Amplification (WGA): How MDA and PCR-Based Methods Differ
Whole genome amplification copies small DNA samples for sequencing. Compare MDA, DOP-PCR and MALBAC using independent single-cell data.
DNA Polymerase I (Pol I): Functions and Klenow Fragment
What E. coli DNA polymerase I does, how the Klenow fragment differs, and how Pol I compares with Pol II, Pol III and Taq, with a sourced activity map.
Lipopolysaccharide (LPS): Structure, Lipid A and TLR4
Lipopolysaccharide (LPS) has three domains; lipid A is detected via LBP, CD14 and TLR4-MD2. How structure shapes the response, with LPS vs LOS.
HEPES Buffer: What It Is, pKa, Range and Cell-Culture Use
What HEPES is, its pKa and molecular weight, typical 10-25 mM culture-media use, HEPES vs Tris, and the light and riboflavin caveat.
Restriction Enzyme Name Index & Cut Sites
Decode restriction enzyme nomenclature with an index of recognition sequences, cleavage coordinates, overhang types, and thermal inactivation profiles.
Acid-Fast Staining: Methods, Principle and QC
Understand acid-fast staining principles, Ziehl-Neelsen and Kinyoun protocols, counterstain chemistry, slide reading, and essential lab quality controls.
Restriction Fragment Length Polymorphism (RFLP)
Restriction fragment length polymorphism (RFLP) detects DNA sequence variations via restriction endonuclease cleavage and gel or Southern blot separation.
Monocyte to Macrophage Differentiation
Learn how monocytes differentiate into macrophages, comparing in vivo migration and in vitro M-CSF protocols with IUIS surface markers and polarization.
Terminal Deoxynucleotidyl Transferase (TdT): Function, Metals and TdT-Positive Cancers
What terminal deoxynucleotidyl transferase does, which metals it uses, how it drives TUNEL and 3′ tailing, and where TdT staining is positive or negative.
Lysozyme: Molecular Weight, Activity Assay, Stock Prep
Bench datasheet for lysozyme covering 14.3 kDa molecular weight, pI 11.35, Shugar turbidimetric activity assay, stock preparation, and bacterial cell lysis.
Induced Pluripotent Stem Cells: iPSC Lab Guide
A laboratory guide to induced pluripotent stem cells (iPSCs): derivation factors, feeder-free culture, ISSCR quality benchmarks, and clinical trial status.
Histopathology: Workflow, Standards, and QC
Master the histopathology workflow from fixation to staining, covering NSH technical standards, AAVLD quality control, and preclinical study guidelines.
Quantum Dot: Types, Imaging Uses and Lab Rules
A guide to quantum dots for lab researchers: core-shell nanocrystal physics, fluorescence imaging, handling rules, commercial types, and supplier selection.
Bacteriophage T4: Biology, Protocol & Enzymes
A guide to bacteriophage T4 biology, ATCC propagation and plaque assay protocols, and the essential T4-derived enzymes used in molecular cloning and NGS.
Jurkat Cells: Culture Protocol, CD3 Expression, and Research Applications
Jurkat cells are immortalized human T lymphoblasts used to model TCR signaling, CD3 expression, and IL-2 production in immunology and cancer research.
CE-SDS: Principle, Workflow, and Purity Analysis
Guide to CE-SDS: separation principles, reduced and non-reduced workflows, USP compliance, and comparative performance against slab-gel SDS-PAGE.
Organoid: Definition, Origins, Uses and Limits
Organoid definition, 2009 origin, uses, differences from organs-on-chips, and a sourced limits checklist: no vasculature, stroma or nerves.
Anaerobic Bacteria Culture: Methods, Media and Specimen Handling
How anaerobic bacteria are cultured: jar vs chamber atmospheres, media, oxygen indicators and a specimen-suitability checklist, from sourced lab guidance.
B-27 Supplement (Neuronal Cell Culture): What It Is and How It Is Used
What B-27 supplement is, how it is used with Neurobasal medium for CNS neurons, B27 vs B27 Plus, and a storage checklist.
Drosophila: Research Resources and FlyBase Guide
A researcher guide to Drosophila resources: how to query FlyBase, source strains from the Bloomington Stock Center (BDSC), and manage culture conditions.
Poly-D-Lysine: Cell Culture Coating Guide
A laboratory guide to poly-D-lysine: electrostatic cell attachment mechanisms, PDL versus PLL enzymatic stability, coating volumes, and rinsing protocols.
ChIP-chip (Chip-on-Chip): How the Array Assay Works and How It Differs from ChIP-seq
ChIP-chip (chip-on-chip) reads ChIP on a DNA microarray. See how it works and how it compares with ChIP-seq on resolution, noise, coverage and cost.
HEK 293 Cells: Origin, 293T Derivative, Media and Authentication
HEK 293 and 293T explained: origin, ATCC-listed media and freezing, biosafety and Cellosaurus authentication, with a sourced side-by-side table.
Cytotoxicity: Definition, Assays and ISO 10993-5 Testing
Cytotoxicity explained: what it means, how in vitro assays (MTT, LDH, dye exclusion) differ, and what FDA says about ISO 10993-5 testing.
NEB Tm Calculator: How It Sets Annealing Temperature and When to Override It
How the NEB Tm calculator sets PCR annealing temperature, how it differs from other Tm tools, and what to do when the calculated value fails.
Saccharomyces cerevisiae: Model Organism, Strains and Reference Genome
Saccharomyces cerevisiae is budding yeast: a model organism with the first finished eukaryotic genome, used in baking and brewing; strains and SGD resources.
Optogenetics: How It Works, Opsins and Chemogenetics Compared
What optogenetics means, how opsins, delivery and light work, optogenetics vs chemogenetics, and the 2026 Nobel Prize in Physiology or Medicine.
Recombinant Inbred Lines (RILs): How They Are Made and Used in QTL Mapping
How recombinant inbred lines are made, when to choose RILs or near-isogenic lines for QTL mapping, and how MGI names RI strains such as BXD.
Acid Detergent Fibre (ADF): Definition, Van Soest Method and Lab Analysis
What acid detergent fibre is, how the Van Soest/AOAC 973.18 method measures it, which acid is used, and how ADF links to lignin and cellulose.
What Is an Epifluorescence Microscope?
Epifluorescence microscope explained: how excitation light passes through the objective, what the filter cube does, and inverted vs upright stands.
XRF Gun (Handheld XRF Analyzer): Detection, Accuracy, Safety
What an XRF gun (handheld XRF analyzer) detects, what limits its accuracy, and the lab safety checklist, from EPA Method 6200 and an FBI lab SOP.
Radiation Symbol: Meaning, Origin and Rules for the Trefoil
The radiation symbol (trefoil): its 1946 Berkeley origin, the colour rules in 10 CFR 20, posting wording, and how it differs from the biohazard symbol.
Restriction Endonuclease: Types, Palindromic Sites and Isoschizomers
Restriction endonucleases (restriction enzymes) explained: Types I-IV compared, palindromic sites, isoschizomers vs neoschizomers, and how enzyme names work.
pH Measurement Instruments: Meters and Probes
Meter, probe and electrode explained, with a sourced table of pH probe variants and a calibration and care checklist.
Multi-Electrode Array (MEA): Types, Sizes and Materials
What a multi-electrode (microelectrode) array is, how passive and CMOS types differ, and which electrode sizes and materials are reported.
Scanning Probe Microscope: How It Works, Types, Uses
How a scanning probe microscope works, the main SPM types including STM and AFM, sourced resolution values and typical research uses.
Saline-Sodium Citrate (SSC) Buffer: Recipe, Dilutions, Use
Saline-sodium citrate (SSC) buffer explained: FDA 20X, 6X, 3X and 2X recipes, what sodium citrate is, and what to check when making or buying it.
Triphenyltetrazolium Chloride (TTC): What It Is and How TTC Staining Works
TTC (CAS 298-96-4) is reduced to red formazan by living tissue. See how the tetrazolium test works, compared use settings and limits.
Nitro Blue Tetrazolium (NBT): What It Is and What the NBT Test Measures
Nitro blue tetrazolium (NBT, CAS 298-83-9) has three separate uses: a blood test, a blot substrate and a redox dye. A sourced guide to telling them apart.
What Is the Purpose of a Streak Plate? Isolating Colonies
A streak plate gives isolated colonies from a mixed specimen. See how quadrant dilution works, which loops and supplies are needed, and what follows.
Perpetual Inventory System: How It Works and How to Reconcile It to Physical Counts
What a perpetual inventory record is, why it must still be reconciled to physical counts, and the controls to check, sourced to the IRS and 2 CFR 200.
Gram Stain Kits: What Is in One and How to Read the Insert
What a Gram stain kit contains, the role of each reagent, and what to check on the insert, label and safety data sheet before use.
ASTM C127: Relative Density (Specific Gravity) and Absorption of Coarse Aggregate
ASTM C127 covers relative density (specific gravity) and absorption of coarse aggregate: OD, SSD and apparent values, uses in mix design, and exclusions.
ASTM C1260: Accelerated Mortar-Bar Test for Alkali-Silica Reactivity
ASTM C1260 screens aggregate for alkali-silica reactivity in 16 days. See its limits, how it differs from C1293, and where C1778 fits.
NIOSH Method 7400: Asbestos and Other Fibers by Phase Contrast Microscopy
NIOSH Method 7400 counts airborne fibers on a filter by phase contrast microscopy. See its limits, counting rules and how it relates to OSHA 1910.1001.
ASTM C29: Bulk Density (Unit Weight) and Voids in Aggregate, Explained
ASTM C29/C29M measures aggregate bulk density and voids. See the three consolidation conditions, the equipment checklist, and how it differs from C136.
ASTM C518: Heat Flow Meter Thermal Conductivity Test Explained
ASTM C518 measures steady-state thermal conductivity of flat slabs with a heat flow meter. Scope, calibration, conditions and how it compares with C177.
Standard Reference Material (SRM): What It Is and How Certified Values Work
What a standard reference material is, how SRM, CRM and RM differ under NIST definitions, and how to read a certificate and certified values.
How Long Should Unwrapped Items Be Sterilized in an Autoclave? Flash Cycle Times
Unwrapped (flash) autoclave cycles run at 132 °C for 3 to 10 minutes depending on sterilizer type and load (CDC Table 8), and what must go with them.
Cell Proliferation Assay: DNA Synthesis, Dye Dilution and Metabolic Readouts Compared
Which cell proliferation assay reads what: DNA synthesis, dye dilution, DNA content or metabolic activity, and the constraints to check first.
VHP Decontamination: What It Is and Where It Is Used
VHP decontamination vs VH2O2 device sterilization: delivery methods, material limits and CDC’s position on room fogging, with sources.
ASTM C1107: Nonshrink Grout Standard Explained
What ASTM C1107 covers for packaged nonshrink grout, its height-change limits, related standards and the shrinkage it does not test.
What Causes Apoptosis? Extrinsic and Intrinsic Triggers
Apoptosis is triggered through death receptors (extrinsic) or the mitochondria (intrinsic), both converging on caspases. Includes a sourced trigger table.
USP 1116 Explained: Aseptic Processing Environment Monitoring
USP 1116 explained: what the chapter covers, how FDA alert and action levels differ from contamination recovery rates, and how to read a result.
ASTM C76: Reinforced Concrete Pipe Standard Explained
ASTM C76 covers reinforced concrete culvert, storm drain and sewer pipe: five classes, D-load, related standards and what the specification leaves out.
ASTM D792: Density and Specific Gravity of Plastics by Displacement, Explained
ASTM D792 measures density and specific gravity of solid plastics by displacement. See Method A vs B, D1505 and ISO 1183 differences, and edition checks.
Accident in the Lab: What Counts and What OSHA Requires Next
Accident in lab: what counts as one, what OSHA 1910.1450 requires afterward, and what CSB investigators recommended after the Texas Tech explosion.
ASTM C173: Air Content of Fresh Concrete by the Volumetric Method
ASTM C173/C173M explained: what the volumetric air-content test covers, why it suits lightweight aggregate, and the checks that make a result invalid.
ASTM C78: Flexural Strength of Concrete Beams (Third-Point Loading)
ASTM C78 (astm c 78) determines concrete flexural strength on a third-point-loaded beam; what it covers, what changes the result, and what to report.
Laboratory Lighting: Layered Design, Task Lighting and What Standards Say
Layered laboratory lighting from NIH guidance: ambient, bench task and controls, the five visual factors, LED lifetime math and what OSHA does not say.
ASTM D1056: Flexible Cellular (Sponge and Expanded) Rubber Specification Explained
What ASTM D1056 covers: flexible sponge and expanded rubber, its type, class and grade structure, the seven test families, and what to check before citing it.
Gamma Irradiation Sterilization: How It Works and Where It Fits
Gamma irradiation sterilization uses cobalt-60 to sterilize packaged products. What it changes in plastics, what regulators say, and a supply checklist.
ASTM D2488: Visual-Manual Soil Identification vs D2487 Explained
ASTM D2488 describes and identifies soils by visual-manual methods. See its scope, the 75 mm limit and when D2487 must be used for precise classification.
How to Calculate Normality: N = n × M and the mol/L Equivalent
Calculate normality with N = n × M, convert molarity to normality, and see how NIST says to restate it in mol/L.
Spend Analysis: Definition, Steps and Data Pitfalls
What spend analysis is, how GAO describes its five processes, and which scope and data choices change what a lab or clinic purchasing review can see.
Lab Hacks: Which Bench Shortcuts Are Safe, and Which Break the Rules
Which lab hacks are safe? A hack-vs-rule table from the BMBL and OSHA 1910.1450, plus a three-question test for vetting any bench shortcut.
USP 1207 Package Integrity Evaluation: Scope and Use
USP 1207 guides package integrity for sterile products. See its life-cycle phases and how FDA guidance on container closure integrity testing relates.
ASTM C476: Specification for Grout for Masonry
ASTM C476 covers fine and coarse grout for masonry. See how it differs from C1019 and C1093, and how proportion and strength specification work.
Caco-2 Cell Line: Origin, Culture Records and Sublines
Caco-2 (ATCC HTB-37, CVCL_0025): origin, supplier culture conditions, sublines, and where ATCC and Cellosaurus records disagree.
ASTM D4318: Liquid Limit, Plastic Limit and PI Explained
ASTM D4318 covers the liquid limit, plastic limit and plasticity index of soils: methods A and B, preparation choices and device tolerances.
Most Powerful Microscope in the World: The Resolution Record and What “Powerful” Means
The highest-resolution microscope result is 0.02 nm (20 pm) by electron ptychography. What “powerful” means, how it was reached and what limits it.
ASTM D695: Compressive Properties of Rigid Plastics Explained
ASTM D695 explained: what the compressive test covers, the properties it reports, how it relates to ISO 604, and how to read a D695 result.
ASTM C138: Fresh Concrete Density, Yield and Air Content
ASTM C138/C138M covers density (unit weight), yield and gravimetric air content of freshly mixed concrete, and how it sits beside C231 and C173.
Water Aspirator: How It Works, Limits and What Replaces It
How a water aspirator works, what vacuum it reaches (about 10 torr), why some institutions restrict it, and how it compares with dry and oil pumps.
ASTM C1019: Sampling and Testing Masonry Grout
What ASTM C1019 covers: sampling and compression testing of masonry grout, its link to C476 and C1093, and a lab report checklist.
Viral Titer: What PFU, TCID50, FFU and Genome Copies Measure
Viral titer explained: what PFU, TCID50, FFU and genome copies each count, where each assay fails, and what to report with a titer.
ASTM D1002: Lap Shear Strength of Bonded Metals, Explained
ASTM D1002 gives the apparent lap shear strength of adhesively bonded metals. Learn its scope, current edition and why results are not design values.
Liquid Nitrogen Freezer: Types, Build and Specs
Liquid nitrogen freezer explained: tank vs upright types, vacuum-insulated build, vapor vs liquid phase temperatures, and sourced capacity figures.
Deoxyguanosine Triphosphate (dGTP): Role in DNA Synthesis
What deoxyguanosine triphosphate (dGTP) is, how it differs from GTP, and how it is used as a dNTP in DNA synthesis and PCR.
Zymography: How Gel Zymography Detects Proteases
How zymography detects protease activity in gels, what a clear band does and does not prove, and how gelatin zymography compares with ELISA.
What Is Ficoll? Ficoll-Paque, PM400 and Percoll Explained
Ficoll is a Cytiva trademark. Learn how Ficoll PM400, Ficoll-Paque PLUS and Percoll differ, with vendor-stated specifications and a sourcing checklist.
Cell-Free System for Protein Synthesis: Lysate, PURE and Reaction Formats
Cell-free protein synthesis compared: lysate and PURE systems, batch versus continuous-exchange formats, and the criteria sources give for choosing.
Lean Laboratory: What It Means, the Eight Wastes and What the Evidence Shows
A lean laboratory removes non-value-added steps. Eight wastes, the five-step approach and what a 2024 review of seven studies found.
Direct ELISA Assay: How It Works and When It Fits
Direct ELISA assay explained: how a labeled primary antibody detects antigen, the sourced trade-offs, and a checklist for when the format fits.
Bis-Tris Gels: How They Work, MES vs MOPS and When to Use Them
Bis-Tris gels run denatured proteins near neutral pH. See MES vs MOPS, vendor run times and a compatibility checklist for SDS-PAGE.
PCR Product Smear: Causes and How to Diagnose It
A PCR product smear has several causes. Read the no-template control first, then work through template, cycles, annealing and the gel buffer.
Fill Rate: Definition, Formula and Types in Hospital Supply
Fill rate in hospital and public-health supply: three sourced measures, their formulas, worked examples and how they relate to stockouts.
E-Beam Sterilization: How It Works and Where It Fits
E-beam sterilization uses accelerated electrons, not a radioactive source. How it works, what limits it, how it is validated and how the FDA frames it.
ASTM C42: Drilled Cores and Sawed Beams of Concrete Explained
ASTM C42/C42M covers obtaining and testing drilled concrete cores and sawed beams. See its scope, factors that affect core strength, and edition status.
Parts per Million to Molarity: Formula, Table and Worked Examples
Convert ppm to molarity with ppm ÷ (1000 × molar mass) for dilute aqueous solutions. Includes a lookup table, worked examples and code.
ASTM D6913: Sieve Analysis of Soils, Methods A and B Explained
ASTM D6913 covers soil gradation by sieve analysis between 75 mm and 75 µm. Compare Methods A and B, see the scope limits and related standards.
Lab Flooring: Requirements, Types and Specification Checklist
Lab flooring explained: what the BMBL requires by containment level, how NIH describes sheet and resinous floors, and a specification checklist.
Precision Plus Protein Ladder: Dual Color, All Blue and Unstained Compared
Precision Plus protein standards compared: Dual Color, All Blue and Unstained, with reference bands, loading volumes and storage per Bio-Rad.
Forensic Microscope: Types, Comparison Microscope Design and Calibration
How a forensic microscope works, from the comparison microscope optical bridge to digital systems, with the AFTE calibration schedule drawn from NIJ and NIST.
DEPC: What Diethyl Pyrocarbonate Does and When to Use It
DEPC (diethyl pyrocarbonate) inactivates RNases in water at 0.1%. See which buffers it fails in, its effect on enzymes, and DEPC vs nuclease-free water.
Western Blot Kit: What Is in the Box and What Is Not
What a western blot kit contains, how reagent-only and matched stack kits differ, capacity and storage from manufacturer manuals, and what you must supply.
DNA Purification: Methods and How Each Works
DNA purification methods compared: silica columns, magnetic beads, precipitation and organic extraction, with vendor yield figures by sample type.
Stereology: How 3D Counts and Volumes Are Estimated From Sections
Stereology estimates 3D volume, number, length and surface area from sections. Compare probes by quantity and avoid common sampling pitfalls.
Cell Dilution Calculator: Formula, Seeding Table and Examples
Cell dilution calculator with the C1V1 formula, a per-vessel stock volume table, worked examples and Excel, R and Python code.
Golgi Stain: What It Labels, Main Variants and How to Read the Results
The Golgi stain labels a sparse, random subset of neurons in full. Compare rapid Golgi, Kopsch and Cox variants and learn how to read the results.
ASTM E1417: Liquid Penetrant Testing Practice Explained
ASTM E1417 covers minimum requirements for liquid penetrant testing of nonporous components; a cross-walk of E1417, E165, AMS 2644 and the written procedure.
Plasmid Preparation: Scales, Grades and How Alkaline Lysis Works
Plasmid preparation explained: how alkaline lysis works, kit-free versus silica-membrane kits, and how to match yield and grade to the downstream use.
Cell Cycle Analysis by Flow Cytometry (FACS): DNA Content, Stains and QC
Cell cycle analysis FACS reads DNA content: 2N and 4N peaks, a stain-by-constraint table, nuclei QC and doublet gating, and how S phase is measured.
How to Grow Algae in the Lab: Media, Light, and Transfers
How to grow algae in the lab: the medium, 20 °C and 12/12 h light, aseptic transfer and subculture schedule a major culture collection uses.
Inventory Shrinkage: What It Is and How Labs and Clinics Handle Loss
Inventory shrinkage is the gap between recorded and counted stock. See what 2 CFR 200.313 and 21 CFR 1301.76 require when equipment or drugs go missing.
Tryptic Soy Broth (TSB): Formula, Uses, and Quality Control
Tryptic soy broth (soybean-casein digest) explained: stated formula, ingredient roles, supplements, and the quality checks on a manufacturer spec sheet.
What Is TEMED? Role in Polyacrylamide Gel Polymerization
What TEMED is, how it works with APS to set polyacrylamide gels, its shelf life against APS, and a sourced checklist for gels that fail to polymerize.
Plasmid and Antibiotic Resistance: How Resistance Genes Travel and Why Labs Use Them
How plasmids carry and spread antibiotic resistance genes, why labs use the same genes as selection markers, and the seven common selection antibiotics.
PFOS and PFOA: What They Are and How They Are Regulated
PFOS and PFOA are persistent PFAS with an EPA drinking water limit of 4.0 ppt each. Compare them, see the regulatory dates and how labs measure them.
What Is the Function of Primers in a PCR Reaction?
Primers anneal to the flanking regions of the target DNA and give the polymerase a 3′ end to extend. See what they do at each PCR step.
Customs Bond: Single vs Continuous and How CBP Sets the Amount
A customs bond secures U.S. import duties and compliance. Single vs continuous bonds, the $50,000 formula, STB amounts and CBP review rules from 19 CFR 113.
Invoice Processing: Steps, the Proper-Invoice Test, and the Payment Clock
Invoice processing explained: the receipt-to-payment steps, what makes an invoice proper under US federal rules, and how the 30-day payment clock is counted.
Cas12a (Cpf1): How It Cuts DNA and How It Differs from Cas9
Cas12a (Cpf1) is a crRNA-guided DNA nuclease with a T-rich PAM, staggered cuts and trans-cleavage of single-stranded DNA.
Molarity to Millimoles: Formula, Table and Worked Examples
Convert molarity to millimoles with mmol = M × mL. Includes a molarity-by-volume table, two worked examples and Excel, R and Python snippets.
HT-29 Cell Line: Origin, Characteristics and Culture Facts
The HT-29 cell line is a human colorectal adenocarcinoma line isolated in 1964. Origin, ATCC culture specifications, identity checks and what a cell line is.
Colony Formation (Clonogenic) Assay: What It Measures and Where Counts Go Wrong
The colony formation assay scores whether single cells divide into colonies of 50+ cells, and where plating efficiency and counting go wrong.
Japan PMDA: What the Pharmaceuticals and Medical Devices Agency Does
PMDA is Japan’s agency for drug and device review, post-marketing safety and relief services. See what each service covers and where to find safety notices.
Lab Ops: What Laboratory Operations Covers
Lab ops is the systems-and-infrastructure side of lab management: procurement, maintenance, safety and SOPs, with OSHA’s Chemical Hygiene Plan as a checklist.
DNA Microarray Analysis: How Arrays Work and What the Data Show
DNA microarray analysis explained: how probes, hybridization and fluorescence work, expression vs SNP use, and arrays vs sequencing, per NHGRI.
STORM Microscopy: How Stochastic Optical Reconstruction Works
STORM microscopy explained: single-molecule localization, STORM vs dSTORM vs PALM, dye photons and duty cycle, and what limits resolution.
ASTM D4541: Pull-Off Strength of Coatings, Explained
ASTM D4541 covers pull-off strength (adhesion) of coatings with portable testers: what it measures, protocols 1 and 2, edition changes and what to report.
ASTM C136: Sieve Analysis of Aggregates Explained
ASTM C136 explained: what the sieve analysis method covers, what it cannot measure, and how C117, E11 and C637 relate to it.
USP 790 Visible Particulates in Injections: What It Requires and What It Does Not
USP 790 requires visual inspection of injections for particulate matter. See its scope, how it differs from FDA draft guidance, and common misreadings.
Declaration of Conformity: What It Is, What It Contains and Who Signs It
A declaration of conformity is the manufacturer’s signed statement that a product meets legal requirements. See its fields, signatory and 10-year retention.
Isothermal Amplification: How LAMP, NASBA, HDA and SDA Differ from PCR
Isothermal amplification copies nucleic acids at a constant temperature. Compare LAMP, NASBA, HDA and SDA by temperature, enzymes, primers and stated limits.
ASTM D412: Rubber and Elastomer Tension Test Explained
ASTM D412 tests the tension of vulcanized rubber and thermoplastic elastomers: two methods, scope limits, and a checklist for comparing results.
What Are Explants? Definition, Sources and Lab Safety Context
Explants are tissue pieces moved to a culture medium. Definition, plant vs human scope, and why primary human explants fall under OSHA’s bloodborne rules.
Stem-Loop (Stemloop) Structures: Histone mRNA Example and RT Primers
What a stem-loop (hairpin) is, the 26-nucleotide histone mRNA stem-loop bound by SLBP, and how stem-loop RT primers are used for miRNA qPCR.
LB Agar Composition: Ingredients per Litre and How Recipes Differ
LB agar composition per litre from Addgene and DSMZ, how the agar and salt amounts differ between recipes, and how plates are made.
MCF-7 Cell Line: Origin, Identity and Culture Basics
MCF7 (MCF-7) is a human breast adenocarcinoma cell line, ATCC HTB-22. Origin, synonyms, STR identity checks and sourced culture conditions.
HCT116 Cell Line: Origin, Identity and Culture Basics
HCT116 (misspelled HTC116) is a human colorectal carcinoma line, CCL-247 / CVCL_0291: origin, KRAS G13D genotype, medium and where reported values differ.
CCK-8 Assay: How It Works, What It Measures and Where It Misleads
The CCK-8 assay uses WST-8 to report dehydrogenase activity in living cells. Learn the stated parameters, vendor differences and common pitfalls.
Request for Information (RFI) Template: What Goes In One and What It Does Not Commit You To
RFI template outline tied to FAR 15.201 and 52.215-3: what to ask, why responses are not offers, and why the FAR sets no required format.
HeLa Cells Origin: Henrietta Lacks, the Cell Line, and What It Means for Your Lab
The origin of HeLa cells in a 1951 biopsy from Henrietta Lacks, what the ATCC record documents, and how the 2013 NIH agreement shapes lab practice.
CRISPR Pros and Cons: What Genome Editing Does Well and Where It Falls Short
CRISPR pros and cons for genome editing: sourced advantages, limits such as delivery and off-target effects, and research versus clinical use.
ISO 17034: Reference Material Producer Competence Explained
ISO 17034 explained: scope, how it replaced ISO Guide 34, and how ILAC-P10 links accredited producers to CRM traceability in the lab.
Culturing Microorganisms: Media, Oxygen and Biosafety
How microorganisms are cultured: medium, vessel, oxygen class and biosafety level, with an E. coli example.
How to Calculate Osmolarity: Formula, Worked Examples and Label Check
How to calculate osmolarity: multiply molarity by particles per solute and sum. Worked NaCl, CaCl2 and sucrose examples plus a 0.9% saline label check.
HepG2 Cell Line: Origin, Identity and Culture Basics
HepG2 is a human liver cell line (ATCC HB-8065) sold as hepatocellular carcinoma but shown in 2009 to be hepatoblastoma-derived. Culture basics and a checklist.
Dissolution Testing: Purpose, Apparatus, and Specifications
What dissolution testing measures, why FDA uses it for tablets and capsules, basket vs paddle apparatus, and specifications vs f1/f2 comparisons.
Fibroblast Functions: ECM Production, Wound Repair, Signaling and Fibrosis
Fibroblast functions explained: ECM production, wound repair, immune cross-talk and fibrosis, plus why tissue and activation state change the answer.
Conjugate Protein: Conjugated Proteins vs Protein Conjugates
Conjugate protein means two things: a protein with a prosthetic group, or a protein covalently linked to a drug, polymer or carrier. See the split.
CT26 Cell Line: Origin, Identity and Culture Basics
What the CT26 cell line is: a BALB/c mouse colon carcinoma line, its CT26.WT clone, genotype markers, culture and storage per ATCC.
Protein Marker (Protein Ladder): Types, Uses and Limits
What a protein marker is, how prestained, unstained and IgG-binding ladders differ, and the size and transfer caveats manufacturers state.
ASTM C31 (C31M): Making and Curing Concrete Test Specimens in the Field
ASTM C31/C31M covers making and curing concrete cylinders and beams in the field. Scope, curing routes, exclusions and a lab intake checklist.
XTT Assay: How It Works, Controls and Kit Differences
How the XTT cell viability assay works, the controls to include, and how two vendor protocols differ in incubation, reagent ratio and wavelengths.
Cryosectioning: What It Is, What It Requires, and Where It Fits
What cryosectioning is, how two core-facility protocols compare, and the consumables, equipment and safety points a frozen-section lab needs.
EdU Assay: How Click Chemistry Detects DNA Synthesis, and How It Differs from BrdU
How an EdU assay detects DNA synthesis by click chemistry, how it compares with BrdU, what the signal does not show, and manufacturer planning points.
Protein Refolding: Methods, Aggregation and How to Check It Worked
Protein refolding returns denatured inclusion-body protein to its active fold. Compare dilution, dialysis and fed-batch, and see how to check for aggregation.
Argonaute Proteins: Domains, Human AGO1-4 and How Slicing Works
Argonaute (Ago) proteins hold the guide in RNA silencing. See what each domain does, why only human AGO2 cleaves, and how prokaryotic Agos differ.
What Is a Biological Buffer? Definition, Good’s Criteria and How to Choose
A biological buffer holds pH steady for enzymes, cells and proteins. See Good’s criteria, a pKa table of nine buffers and how to choose by target pH.
U-2 OS Cell Line: Origin, Identity and Culture Basics
U-2 OS (U2OS) is a human osteosarcoma line, ATCC HTB-96. Origin, names and identifiers, culture conditions and what to record when reporting it.
Protein Phosphatases: What They Do, Main Families, and Why Labs Care
What protein phosphatases do, how the PPP, PPM and PTP families differ, and why phosphorylation state matters at the bench.
ATPase Assay: What It Measures, Four Readouts and Where Each Misleads
What an ATPase assay measures, how four readouts compare on sensitivity and failure modes, and the controls and consumables each one needs.
In Silico PCR: What It Is and How to Read Results
What in silico (virtual) PCR predicts, how UCSC In-Silico PCR and Primer-BLAST differ, and why a predicted amplicon is not a validated assay.
Snyder Agar Test: What It Measures, How Results Are Graded, and Its Limits
What the Snyder agar test measures, how its colour change is graded under four schemes, the control checks to run, and how accurate it is.
PCR for Genotyping: Reading Bands, Controls and Limits
How PCR genotyping assigns alleles, what the IPC and PHet controls prove, and why end-point PCR cannot separate hemizygous from homozygous animals.
Digital Holographic Microscopy: How It Records Phase and What Label-Free Cell Imaging Can Measure
Digital holographic microscopy reconstructs amplitude and phase from a hologram, imaging living cells without contrast agents. What it can and cannot measure.
HE Agar (Hektoen Enteric Agar): What It Selects For and How to Read Colonies
HE agar is Hektoen enteric agar, a selective and differential plate for Salmonella and Shigella. How it works and how to read typical and atypical colonies.
Positional Cloning: How a Disease Gene Is Found by Its Location
Positional cloning locates a disease gene by chromosome position, not protein function. See how it differs from functional cloning, with the 1989 CF example.
S. pyogenes Gram Stain: Gram-Positive Cocci in Chains
S. pyogenes Gram stain: purple gram-positive cocci in chains, how the stain works, and what it cannot show about hemolysis or Lancefield group.
Thermal Shift Assay (DSF): How It Works and Reading Tm Curves
Thermal shift assay (DSF) explained: how dye fluorescence gives protein Tm, how to read the curve, and the real-time PCR equipment it runs on.
MHA Agar: Mueller-Hinton Agar Specs and Uses
MHA agar is Mueller-Hinton agar, the disc diffusion medium. See how pH, depth and cations shift zones and how 21 brands compared.
CETSA (Cellular Thermal Shift Assay): What It Measures, Formats and Limits
CETSA tests drug-target binding in intact cells via thermal stability. See the two experiment designs, four readouts compared, and what the assay can miss.
FDA Investigations Operations Manual (IOM): What It Is and How Labs Use It
What the FDA Investigations Operations Manual is, how its ten chapters are organised, and which inspection forms (482, 483, 484) a lab or clinic may see.
Salmonella Gram Stain: Gram-Negative Rods and What the Stain Cannot Show
Salmonella is a Gram-negative rod and stains pink to red. See why the stain cannot confirm Salmonella and how culture does.
Nodular Roots: What Root Nodules Are and How Nodulation Works
Nodular roots carry nodules where bacteria fix nitrogen for the plant. See how root nodulation works and how determinate and indeterminate nodules differ.
ddPCR (Droplet Digital PCR): How It Works and What to Report
How ddPCR splits a reaction into droplets, counts positives and applies Poisson correction, with a worked example and what dMIQE 2020 says to report.
Mass Photometry: How It Measures Single-Molecule Mass
Mass photometry is a label-free method that weighs single biomolecules in solution by their light scattering, showing each species as a peak.
Recombinase Polymerase Amplification (RPA): How It Works
Recombinase polymerase amplification (RPA) copies DNA at constant temperature. See its components, reported conditions and design limits.
ASTM D4169: What the Shipping Container Performance Standard Covers
ASTM D4169-22 explained: the lab practice for testing shipping units against distribution hazards, how it differs from ISTA, and what to ask a test provider.
Protein Motif: Definition, Types, and How to Read a Motif Pattern
What a protein motif is, how PROSITE and RCSB write and search motifs, and how to read a pattern such as N-{P}-[ST]-{P} symbol by symbol.
ATP Assay: What It Measures and Where It Misleads
How the ATP assay works for cell viability and surface hygiene swabs, which question each readout answers, and where the numbers mislead.
SYBR Green Real-Time PCR Protocol: Setup, Cycling and Melt Curve
A SYBR Green real-time PCR protocol: reaction setup, how to choose standard or fast cycling, the melt curve stage, and NTC checks.
What Is Category Management? Definition and Use in Procurement
Category management is buying common goods and services as an enterprise. See the OMB definition, the Tier 0-3 spend model and the Medical category.
Phusion PCR Protocol: Reaction Setup, Cycling and Troubleshooting
Phusion PCR protocol: reaction setup, cycling times per kb, HF vs GC buffer, which Phusion product to use, and fixes for no product or smears.
Gene Notation: Genotype Symbols, Alleles and HGVS Variants
Gene notation explained: what genotype letters like tt mean, how human and mouse gene symbols differ, how allele superscripts work and how to read HGVS.
Air Changes per Hour (ACH): Formula, Calculation and What the Numbers Mean
Air changes per hour is airflow divided by room volume. Learn the ACH formula, a worked example and what CDC removal-time data says.
K562 Cell Line: Origin, Identity and Culture Basics
K562 cell line explained: origin from a CML patient, the several names it goes by, ATCC culture basics, and why repository STR profiles differ.
Importer of Record: What It Means and Who Is Liable
Importer of record under U.S. customs rules: who counts as the importer, what CBP Form 5106 does, and why paying a broker does not shift liability.
ASTM D638: Tensile Properties of Plastics Explained
ASTM D638 tests tensile properties of plastics on dumbbell specimens up to 14 mm thick; D882 covers film under 1.0 mm. What to record in a report.
Lab Automation: What It Is and How Automation Standards Fit Together
What lab automation covers, why plate-footprint and communication standards are separate layers, and what to check before specifying a system.
Cas13 (CRISPR-Cas13): How It Targets RNA, Collateral Cleavage and Uses
Cas13 is a CRISPR enzyme family that finds and cuts RNA, not DNA. How it works, collateral cleavage, dCas13 uses, subtypes and SHERLOCK diagnostics.
FISH Method (Fluorescence In Situ Hybridization): How It Works and Its Variants
The FISH method locates a DNA sequence on a chromosome with a fluorescent probe. Definition, use, and Fiber-, Q- and Flow-FISH variants compared.
How to Choose Primers for PCR: A Selection Checklist
Choose PCR primers by length, Tm, GC content, 3′ end and specificity. Two published ranges compared side by side, plus a checklist to run before you order.
How Does UV Damage DNA? Thymine Dimers and Repair
Adjacent pyrimidines absorb UV and form CPD and 6-4 photoproduct lesions. Compare how often each forms, how it is repaired and why UVB drives mutation.
ISO 15223-1: What the Medical Device Symbols Standard Covers
ISO 15223-1 specifies the symbols used on medical device labels. See its scope, the 2025 amendment and the US glossary rule in 21 CFR 801.15.
TA Cloning and TOPO Cloning: How It Works
How TA cloning and TOPO cloning join a PCR product to a vector, with a polymerase checklist drawn from the manufacturer user guide.
Fixing Cells: Cross-Linking vs Precipitating Fixatives
How cell fixation works, aldehyde versus methanol fixatives, and a sourced checklist for choosing one for your downstream stain.
Gateway Cloning: How BP and LR Reactions Work
How Gateway cloning moves a gene between vectors with BP and LR reactions, att sites and ccdB selection, with vendor claims checked against the primary paper.
Evaporative Light Scattering Detector (ELSD): How It Works, Parts and Types
How an evaporative light scattering detector works: nebulizer, drift tube and optical cell, single- vs split-flow designs, and temperature settings.
CLIP-seq Explained: How Crosslinking and Immunoprecipitation Map RNA-Binding Protein Sites
How CLIP-seq maps RNA-binding protein sites, how PAR-CLIP, iCLIP and eCLIP differ, and the ENCODE checklist for a credible dataset.
What Is Wafting? The Lab Technique for Smelling a Chemical
Wafting fans vapor toward your nose instead of inhaling over a container. What the NRC and OSHA say, and why odor is never a safety test.
Why Is Mercury Dangerous? Forms, Routes and Health Effects
Why mercury is dangerous: elemental, inorganic and organic forms, how exposure happens, health effects, and the exposure limits labs can look up.
EMSA (Gel Shift) Assay: How It Works, Controls and What a Shift Does Not Prove
EMSA detects protein-nucleic acid binding as a slower band on a native gel. Learn the labels, controls and what a shift does not prove.
ASTM E595: Outgassing Test for TML, CVCM and WVR Explained
ASTM E595 measures total mass loss and collected volatile condensable material from outgassing in vacuum at 125 °C. How the test runs and how to read results.
Vinegar Molarity: Molarity of Acetic Acid in Vinegar (Table and Formula)
Vinegar molarity from percent acidity: a 5 g/100 mL vinegar is about 0.833 M. Lookup table, formula, worked examples and Excel, R and Python code.
CRISPRa (CRISPR Activation): How dCas9 Activators Work and Compare
CRISPRa turns genes up without editing DNA. Compare dCas9-VP64, VPR, SAM and SunTag, plus the controls and caveats labs should plan for.
IEC 60601-1: What the Medical Electrical Equipment Safety Standard Covers
IEC 60601-1 explained: what the medical electrical equipment safety standard covers, which edition and FDA recognition apply, and what falls outside it.
Identifying Bacteria: From Gram Stain to MALDI-TOF and 16S Sequencing
How bacteria are identified, from Gram stain to MALDI-TOF and 16S sequencing, with turnaround and accuracy figures from a routine-lab study.
Lot Number: What It Identifies and How It Differs from a Serial Number
A lot number is a code that traces a batch of product back to its manufacture. FDA definitions, UDI role, and lot vs serial number vs expiry.
Stockout: Definition and Measurement in Labs and Clinics
A stockout is a local, facility-level event. See how health programs measure it, how it differs from a shortage, and what hides it.
Contractor Management: What It Covers and What a Host Employer Owes
Contractor management explained: OSHA multi-employer roles and the host-employer and contract-employer duties in 29 CFR 1910.119(h).
5S Methodology: What the Five S’s Mean and How Labs Use Them
5S methodology explained: the five steps, how they apply in a laboratory, one prep-room case and the environmental trade-offs the EPA flags.
Corrosive Fluids: What Counts as Corrosive (Skin, Metal and Transport Definitions)
Corrosive fluids defined: the OSHA skin and metal tests (6.25 mm/yr at 55 °C, pH 2 or 11.5) and DOT Class 8 packing groups, side by side.
Duty Drawback: What It Is and How the Three Types Work
Duty drawback refunds customs duties on imported goods later exported or destroyed. The three types, the 5-year limit and e-filing rule, from the statute.
What Is ASTM F963? The US Toy Safety Standard Explained
ASTM F963 is the toy safety standard US law makes mandatory: which edition applies, who needs third-party testing, and what a CPC is.
Administrative Controls: Definition, Lab Examples and Limits
What administrative controls are, which ones labs already owe under OSHA 1910.1450, and why they rank fourth in the hierarchy of controls.
Procure to Pay: The Full Cycle From Requisition to Payment
Procure to pay explained: the steps from requisition to payment, who owns each, and the document trail labs and grant-funded clinics must keep.
FITC (Fluorescein Isothiocyanate): Spectra, Labeling and Limits
FITC is a green amine-reactive dye excited at 488 nm. Learn how it labels proteins, where pH and photobleaching limit it, and which dyes share its channel.
MC38 Cell Line: Origin, Identity and Culture Basics
MC38 is a mouse colon adenocarcinoma line (CVCL_B288). Names, identity table, source differences and what to record in methods, plus what a cell line is.
TUNEL Assay: What It Detects, Label Chemistries and Controls
TUNEL assay explained: what DNA breaks it labels, how label chemistries differ, which controls apply and why a positive needs confirming.
ELISpot Assay: What It Measures and How It Differs from ELISA
ELISpot counts individual cytokine-secreting cells. See how it differs from ELISA and flow cytometry, and which plate and reagent choices it requires.
Lowry Assay: Principle, Range, Interferences
The Lowry assay measures protein by copper and Folin reagent color. Working range, wavelengths, interferents with remedies, and how it compares with Bradford.
Use of Condenser in Microscope: Types and Aperture Rules
What the microscope condenser does, how its types compare, and how to set aperture, oil and slide thickness for the objective in use.
Bimolecular Fluorescence Complementation (BiFC): How It Works, Controls and Limits
BiFC reports protein-protein interactions in living cells with split fluorescent proteins. Learn the fragment choices, controls and limits.
Pull-Down Assay: Bait, Prey, Controls and What a Band Proves
How a pull-down assay works: bait and prey, the two negative controls and the false positive each removes, and what a band does not prove.
What Is GFP Protein? Structure, Size and Spectra
GFP is a 238-amino-acid jellyfish protein of about 27 kDa that forms its own green chromophore. Size, spectra and wild-type vs EGFP explained.
CLSI M100: What the AST Breakpoint Standard Covers (36th Edition)
CLSI M100 supplies breakpoint and QC tables for antimicrobial susceptibility testing; the methods live in M02, M07 and M11. 36th edition explained.
Triple Sugar Iron Agar Results: How to Read Slant, Butt, Gas and H2S
How to read triple sugar iron agar results: slant and butt colour, gas and H2S, with expected reactions for three QC strains and the limits of the test.
DNase Agar Test: How the Methyl Green Plate Works and How to Read It
How the DNase agar test works, how methyl green and toluidine blue plates differ, and the control strains labs use to check them.
What Is CellProfiler? Open-Source Cell Image Analysis, Explained
CellProfiler is Broad Institute software that measures cells in microscope images using module pipelines. What it does, 3D and deep learning, and a checklist.
Polyethylenimine (PEI) Transfection: How It Works and What to Optimise
Polyethylenimine (PEI) transfection explained: linear vs branched PEI, DNA to PEI ratios, and what varies between batches.
FLAG Tag (DYKDDDDK): Sequence, 3xFLAG and His-tag
FLAG tag sequence (DYKDDDDK and its DNA), how 3xFLAG differs, and a side-by-side check against the His-tag for expression and purification planning.
PCR Template DNA: How Much to Use and What Ruins It
PCR template DNA is the DNA holding the segment to copy. Learn how much to add by target copies, what inhibits the reaction, and how to avoid carryover.
DNA Barcoding: How a Short Gene Region Identifies a Species
DNA barcoding matches a short standard gene region to a library of vouchered reference sequences. Learn the COI standard, BINs and what a record needs.
Analytical Process: Stages from Sampling to a Validated Result
The analytical process runs from sampling to a result with measurement uncertainty. See how Eurachem VaMPIS and ICH Q2(R2)/Q14 treat each stage.
Cpk Formula: How to Calculate Process Capability (With a Worked Example)
The Cpk formula, a worked calculation with Cp vs Cpk, and the stability, normality and sample-size checks needed before a capability index means anything.
Microwave Sterilization: What the CDC Says for Labs and Clinics
Microwave sterilization per the CDC guideline: listed disinfection uses, conditions that change results, and why device sterilization is not FDA cleared.
Differential Interference Contrast (DIC): How It Works and What It Cannot Measure
How DIC microscopy turns optical-path gradients into contrast, what it cannot measure, and why glass vessels matter.
Dot Blot: What It Detects and What It Cannot Tell You
A dot blot spots samples straight onto a membrane for fast detection, but gives no size information. See what it answers, the controls it needs, and when to use a western blot.
Rolling Circle Amplification: How RCA Works and Where Labs Use It
How rolling circle amplification works: circular templates, phi29 polymerase, isothermal conditions, readouts, and what an RCA workflow needs in the lab.
Tandem Affinity Purification (TAP) Tagging: How It Works
What TAP tagging is, how the two-step native purification of protein complexes works, and what to weigh before using it.
Copy Number of a Gene: What It Means and How It Is Counted
Copy number of a gene is how many copies a genome carries. See how CNV differs from aneuploidy, plasmid copy number and qPCR fold change.
CNA Agar (Columbia CNA with Sheep Blood): What It Selects For and How Makers Differ
CNA agar is Columbia blood agar with colistin and nalidixic acid. See what it selects, what still grows, and how two makers’ formulations differ.
Dendritic Cell Function: How DCs Prime T Cells
How dendritic cells capture antigen, migrate and prime T cells, how subsets differ, and how to read DC assay results from culture models.
Mucicarmine Staining: What It Detects and How to Read It
What mucicarmine staining detects, how to read mucin and Cryptococcus results, and how three vendor kits differ on labelling, colours and controls.
Days Sales of Inventory (DSI): Formula and How Labs Read It
Days sales of inventory explained: the formula, how a real filer defines it, and why expiry and slow-moving stock change how labs and suppliers read it.
Master Mix in PCR: What It Contains and What to Record
What a PCR master mix contains, what you still add, and what two vendors actually disclose, with a record-keeping checklist for labs.
Von Kossa Staining: What It Detects, Results and Limits
Von Kossa staining marks calcium deposits black in paraffin sections. How the silver reaction works, how to read results, and where specificity falls short.
PO Number: What It Identifies and Where It Must Appear on an Invoice
What a PO number identifies, the federal PIID format, and the invoice rule that requires the order number on a proper invoice.
Cell-Penetrating Peptides: Examples, Sequences, and How They Are Classified
Examples of cell-penetrating peptides (TAT, penetratin, transportan, R8, VP22, iRGD) with printed sequences, origins and how they are classified.
PC12 Cell Line: Origin, Identity and Culture Basics
The PC12 cell line is a rat adrenal pheochromocytoma line known for its reversible NGF response; this guide covers origin, identity checks and culture facts.
Listeriosis Gram Stain: What Listeria Looks Like and What the Stain Cannot Tell You
Listeria monocytogenes is gram-positive: purple, small regular rods. See how catalase, hemolysis and motility follow the stain, per the CDC chart.
Methyltransferase: DNA Methyltransferases (DNMTs) Explained
What a methyltransferase does, how DNMT1, DNMT3A and DNMT3B differ, and why methionine synthase is a different enzyme.
Bio-Layer Interferometry (BLI): How It Works, What KD Means, and How It Differs from SPR
Bio-layer interferometry (BLI) measures label-free binding with dip-in biosensors. How it works, what KD means, SPR differences and an artefact checklist.
Prussian Blue Staining: What It Detects, How It Works and Its Limits
Prussian blue (Perls’) staining detects ferric iron such as hemosiderin. What it can and cannot detect, and the handling steps that cause false results.
Multiple Cloning Site (MCS): What It Is and How to Choose Sites
What a multiple cloning site is, why two different MCS enzymes give directional cloning, and a sourced checklist for choosing sites.
Warthin-Starry Staining: What It Detects, How Results Look, and Its Limits
Warthin-Starry staining turns bacteria black on a golden background. What it detects, how it compares with PCR and serology, and the QC points that matter.
Differential Staining: How Gram and Acid-Fast Stains Separate Cells and What Each Result Cannot Tell You
Differential staining separates cell types by color. See how Gram and acid-fast stains work, what each cannot tell you, and the QC controls that catch errors.
Sterilization Technology: Methods, Standards and How They Compare
How steam, ethylene oxide, radiation and vaporized hydrogen peroxide compare, using FDA and CDC guidance and the standards FDA names.
Oil Red O Staining: Frozen Sections and Protocol Variants
Oil Red O stains neutral fat red in frozen sections. Compare three published protocol routes, see why paraffin and ethanol fail, and use a bench checklist.
Comet Assay (Single-Cell Gel Electrophoresis): What It Detects and What to Report
The comet assay measures DNA damage in single cells. What each version detects, how results are scored, and what a methods section must report.
Decalcification: Agents, Endpoints and Effects on Downstream Assays
Decalcification removes mineral from bone and teeth for sectioning. Compare published agent results and effects on nucleic acids and staining.
Multiplexed PCR: How It Works and When Singleplex Wins
Multiplexed PCR amplifies several targets in one reaction: how it is used in genotyping and diagnostics, and the sourced trade-offs against singleplex.
S. pneumoniae Gram Stain: Appearance, Specimens and Limits
What S. pneumoniae looks like on a Gram stain, why the CDC calls it suggestive only, and which sputum criteria and follow-up tests apply.
Polarized Optical Microscopy: How It Works and What It Reveals
Polarized optical microscopy images birefringent material between crossed polarizers. See how it works, what you see, and which components a microscope needs.
Calcium Imaging: How GCaMP Indicators Turn Calcium into Fluorescence
How calcium imaging works, how GCaMP6 slow, medium and fast variants differ, and what a fluorescence trace does and does not say about neuronal spiking.
NIOSH Pocket Guide to Chemical Hazards: What It Contains and How to Read an Entry
What the NIOSH Pocket Guide to Chemical Hazards contains, how to read REL, PEL, STEL and IDLH, and where the guide stops being enough.
Three-Way Match: PO, Receiving Report and Invoice Before Payment
Three-way match explained: which fields must agree across the order, receiving report and invoice, and how federal payment timing rules start the clock.
ASTM E119: What the Fire-Resistance Test Measures and What Ratings Do Not Cover
ASTM E119 measures how long walls, floors, roofs and columns contain fire or carry load. See how ratings are set and what they do not cover.
SOE PCR: Splicing by Overlap Extension Explained
What SOE PCR is, how overlapping ends join DNA fragments, and how to design overlaps, compared across conventional and single-tube methods.
Xylose Lysine Deoxycholate (XLD) Agar: How It Works and How to Read Salmonella Colonies
How XLD agar selects and differentiates Salmonella and Shigella, with a colony-reading table of look-alikes and the QC organism panel.
Bile Esculin Agar Test: How It Works, How to Read It and What the Result Does Not Prove
How the bile esculin agar test works, what blackening does and does not prove, and how maker formulas, controls and intended use differ.
PFGE (Pulsed-Field Gel Electrophoresis): How It Works and Why Labs Moved to WGS
PFGE separates very large DNA fragments with alternating electric fields. How it works, its limits, and why PulseNet USA moved to WGS.
Flame Ionization Detector (FID): How It Works in Gas Chromatography
How a flame ionization detector works in gas chromatography: gases, typical hydrogen and air flows, what it detects and misses, and hydrogen safety.
Fluorophores: Brightness, Stokes Shift and Photobleaching
What fluorophores are, the main types, and how Stokes shift, brightness and photobleaching translate into filter, laser and dye decisions.
How to Calculate Parts Per Million (ppm)
Calculate parts per million (ppm) from masses, mg/kg, mg/L or percent, with worked examples and the density case where the mg/L shortcut fails.
Cell Wall Examples: Which Cells Have Cell Walls?
Cell wall examples: plants, fungi, most bacteria and archaea, and some protists have walls; animals do not. Sourced table of wall components by group.
Elemental Analyzer: How CHNS Combustion Analysis Works, Types and Specs
How a CHNS elemental analyzer works, which detector measures which element, instrument types, and a sourced LECO 828 vs 928 specification comparison.
Goods Receipt Note (GRN): What It Records and Why It Gates Payment
A goods receipt note records what arrived, how many and who accepted it. See the FAR 32.905 field list and why acceptance timing matters for payment.
Formation of Spores in Bacteria: The Stages of Endospore Development
Stages of bacterial endospore formation in Bacillus subtilis, which cell compartment controls each, and what the coat, cortex and DPA protect against.
Dark Field Microscopy: How It Works, NA Rules and When to Use It
How dark field microscopy works, the condenser and objective NA rule, a setup checklist, and which specimens suit darkfield illumination.
Seahorse Assay: What It Measures and How to Read a Mito Stress Test
What a Seahorse assay measures, how the Mito Stress Test injections map to respiration parameters, and the pitfalls to check when comparing wells.
Plaque Assay: What It Measures, How PFU Is Counted, and Its Limits
A plaque assay counts infectious virus as plaque-forming units per mL. See how it works, how it compares with focus assays and qPCR, and its limits.
Transmission Electron Microscope Images: Types and How to Read Them
How to tell bright-field, dark-field, diffraction, lattice and STEM images apart, and what each TEM picture does and does not show.
Auramine-Rhodamine Staining: How the Fluorescent AFB Stain Works
How auramine-rhodamine staining works, what the evidence shows against Ziehl-Neelsen, and a sourced quality and supply checklist for labs.
Eastern Blot: What the Term Means, Variants and How to Read It
The eastern blot is a non-standardized term for blotting modifications on proteins or lipids. Variants compared, plus a methods-section checklist.
Histological Staining: Routine, Special and Advanced Stains Explained
How routine, special and advanced histological stains differ, what each common stain shows, and what keeps results consistent.
Illumina/Solexa Sequencing: How Sequencing by Synthesis Works
How Illumina/Solexa sequencing by synthesis works, what the Solexa name means today, and how it differs from ion semiconductor sequencing.
Confined Space: OSHA Definition, Permits and the Entry Permit Checklist
Confined space explained: the OSHA three-part definition, permit-required spaces, and the 15 items a confined space entry permit must identify.
SPC Charts: Control Limits, Constants Table and Worked Examples
How SPC charts set control limits: formulas, the A2/D3/D4 constants table for subgroups of 2 to 10, worked examples, and Excel, R and Python code.
Congo Red Staining for Amyloid: Readouts and Pitfalls
How Congo red staining detects amyloid: polarized-light and fluorescence readouts compared, plus the coverslip, optics and control pitfalls to document.
Reverse Transcription PCR (RT-PCR): One-Step vs Two-Step
Reverse transcription PCR converts RNA to cDNA before amplification. See one-step vs two-step formats, RT primer options and how to avoid genomic DNA.
ELISA Antibodies: Capture, Detection and Matched Pairs Explained
Which antibodies an ELISA uses, what capture and detection antibodies do in each format, and the checklist that makes two antibodies a matched pair.
THP-1 Cell Line: Origin, Identity and Culture Basics
What the THP-1 cell line is, where it came from, how ATCC lists its culture, and how sources differ on doubling time, HLA and STR.
What Is a Protoplast? Definition, Formation and Uses
A protoplast is a cell with its wall removed. Definition, how protoplasts form, how they relate to spheroplasts, and where they matter in gene editing.
Reverse Complement of DNA: What It Is and How to Get It
The reverse complement of DNA swaps each base for its pair and reverses the order. Worked example, tool options, and where it matters in the lab.
Immunostaining: What the Term Covers (IHC, ICC and IF Explained)
Immunostaining detects a target protein with an antibody. See how IHC, ICC and IF differ by sample and readout, and which controls to report.
SCNT Cloning: Somatic Cell Nuclear Transfer Explained
SCNT cloning replaces an egg nucleus with a somatic cell nucleus. What it is, how it differs from gene cloning, and the consent rules that apply.
MacConkey Agar: How It Works and How to Read Results
MacConkey agar explained: what makes it selective and differential, why lactose fermenters turn pink, and a QC organism table from a manufacturer data sheet.
Classical Complement Pathway: Activation, Components and Regulation
How the classical complement pathway is activated by C1q, how it differs from the lectin and alternative pathways, with regulators and deficiencies.
Z-N Staining: What the Ziehl-Neelsen Stain Detects and How to Read It
Ziehl-Neelsen (Z-N) staining finds acid-fast bacilli. How it works, the 1% carbol fuchsin update, an example AFB grading scale and a QC and safety checklist.
Inverted Microscopy: How It Works and When to Use It
Inverted microscopy places objectives below the stage so dishes and flasks sit on top. See how it works and which vessel bottoms suit it.
Proximity Ligation Assay (PLA): What the Signal Does and Does Not Prove
How a proximity ligation assay turns close protein pairs into countable spots, with a controls checklist and the limits of reading a signal.
Kirby-Bauer Test: How Disk Diffusion Susceptibility Works
The Kirby-Bauer test explained: how disk diffusion works, the EUCAST standard conditions, and which setup errors shift zone sizes.
Lipofectamine 3000 Protocol: Per-Well Amounts, Steps, and siRNA Differences
Lipofectamine 3000 protocol with per-well amounts for 96-, 24- and 6-well plates, the two-dose test, and how siRNA differs from plasmid DNA.
ASTM F2413: What the Safety Footwear Standard Covers (F2413-24)
ASTM F2413 sets minimum performance requirements for safety toe cap footwear. See its scope, the F2412 test codes, and how F2413-24, -18 and OSHA relate.
Inhibitory Neurotransmitter: GABA, Glycine and How Inhibition Is Tested
What an inhibitory neurotransmitter is, how GABA-A, GABA-B and glycine receptors differ, and how antagonist pharmacology identifies which one is responsible.
Giemsa Staining: How Blood Films Are Stained and When Wright-Giemsa Is Not Enough
Giemsa staining for blood films: CDC-listed stain strength, buffer pH, thin vs thick film handling, Wright-Giemsa vs Giemsa and a QC checklist.
Supercoiled DNA: What It Is and How Topoisomerases Change It
Supercoiled DNA is DNA under torsional stress. Learn linking number, negative vs positive supercoiling, and how type I, type II and gyrase change it.
DNA Imprinting (Genomic Imprinting): What It Is and How It Is Tested
DNA imprinting silences one parental copy of a gene without changing the sequence. How it works, how loci fail, and how methylation testing screens for it.
Genes and Behaviour: What Heritability and Twin Studies Show
How genes relate to behaviour: what heritability, twin studies and missing heritability do and do not show, for researchers and study designers.
How to Get Molarity from pH: Formula, Table and Examples
Get molarity from pH with [H+] = 10^-pH: formula, a pH 0-14 table of H+ and OH- molarity, worked examples, and Excel, R and Python code.
Lipofection: How Lipid-Based Transfection Works and When to Use It
Lipofection uses cationic lipid transfection reagents to deliver DNA, RNA or protein into cells. How it works, how lipids differ, and when to choose it.
How to Calculate pH from Molarity: Formula, Table and Worked Examples
Calculate pH from molarity for strong acids and bases: formula, lookup table, worked examples, spreadsheet and code snippets.
ASTM D4236: What the Art Materials Label Standard Requires
ASTM D4236 is the art-materials chronic-hazard labeling practice made federal law by LHAMA. What a conforming label must contain, and what it does not mean.
Superior Colliculus (Colliculus Superior): Function and Layers
Colliculus superior is the superior colliculus: a layered midbrain structure for orienting. Function, layers, and how labs study it, from three reviews.
Mitochondria and Function: Structure, ATP and Repair
Mitochondria generate most of a cell’s ATP. Learn their structure, matrix vs intermembrane space, plant-cell roles and how damage is repaired.
Triple Point of Water: 273.16 K, What It Is and How Labs Use It
The triple point of water is 273.16 K (0.01 °C), where ice, liquid and vapor coexist. How labs use it to calibrate thermometers since the 2019 SI change.
Incoterms 2020 Explained: The 11 Rules, Chart and What They Do Not Cover
The 11 Incoterms 2020 rules by transport mode, what changed from the 2010 edition, and the contract points Incoterms do not decide.
Graphene: What It Is and What It Is Used For
Graphene is a single atomic layer of carbon. See what it is used for in electronics and metrology, and why standardisation is its biggest problem.
DNA and Nucleotides: How Nucleotides Build DNA and How RNA Differs
DNA and nucleotides explained: what a nucleotide is, how nucleotides build DNA, and how RNA differs, with a sourced comparison table.
FDA 510(k) Data: What the Database Contains and How to Search It
What FDA 510(k) data contains, how the search form, downloadable files and openFDA differ, and which FDA medical device database to use.
Fisher’s Exact Test: What It Tests and What Software Reports
Fisher’s exact test for 2×2 tables: when to use it over chi-square, what a calculator needs, and why packages disagree on p-values and odds ratios.
Kinesin Protein: What It Is and How It Walks Along Microtubules
Kinesin is a motor protein that uses ATP to carry cargo along microtubules in 8 nm steps. Parts, step cycle and how to read a kinesin PDB record.
Lox-Stop-Lox (LSL): How the Cassette Works
A lox-stop-lox cassette is a loxP-flanked STOP that Cre removes to activate a gene. Worked K-ras example, three uses and how excision is confirmed.
Dihybrid Cross: 9:3:3:1 Ratio and Worked Example
A dihybrid cross follows two traits at once. See the 9:3:3:1 ratio, a worked pea example, monohybrid comparison and when the ratio does not hold.
What Is an Aqueous Solution? Definition, Non-Aqueous Contrast and Solubility Limits
What is an aqueous solution? Water is the solvent. Learn the non-aqueous contrast, solubility limits and what a lab solution label should state.
Mean Square Displacement (MSD): Definition, Calculation and Fitting Diffusion Coefficients
Mean square displacement explained: the MSD formula, a worked calculation, how to fit a diffusion coefficient and how many points to use.
Axon and Axon Hillock: Structure and Where Spikes Start
The axon hillock is the base of the axon; the initial segment beyond it is where spikes usually start. Sourced distances, channels and common mix-ups.
How to Calculate Molar Mass: Steps, Examples and Which Atomic Weights to Use
How to calculate molar mass: sum atomic weights by atom count, with worked examples (H2O, NaCl, a hydrate) and the atomic-weight intervals to record.
Sigmoidal Graph: Equation, Shape and Lab Uses
Sigmoidal graph explained: the sigmoid equation, dose-response fitting with EC50 and HillSlope, and why the oxygen dissociation curve is S-shaped.
Transformation in Bacteria: Definition, Steps, and What Each Step Is For
Transformation in bacteria is the uptake of foreign DNA by a cell. Learn the steps, what each is for, and what to check when no colonies grow.
Scanning Tunneling Microscopy (STM): How It Works and What the Image Shows
How scanning tunneling microscopy works: tunneling current, feedback loop, constant-current vs constant-height imaging, and how to read an STM image.
What Is Biotinylated? Biotinylation, Reversibility and Checks
Biotinylated means carrying covalently attached biotin. See the chemistry by target group, how reversal works and how to confirm labeling.
Pareto Chart: How to Build One, With a Lab Worked Example
A Pareto chart ranks causes by frequency with a cumulative line. Sourced lab table, formula, rounding, a re-weighted second example, and Excel/R/Python code.
Molal Formula: Molality = Moles of Solute per Kilogram of Solvent
The molal formula is b = moles of solute / kilograms of solvent, in mol/kg. Units, worked examples, molal vs molar, and NIST reporting wording.
How to Make a 10% Bleach Solution (1:10 Dilution)
Make a 10% bleach solution: 1 part bleach to 9 parts water. Resulting strength, when 1:10 is used, shelf life and mixing hazards, per CDC.
Compound Microscope Optics: The Light Path, Magnification and Numerical Aperture
How a compound microscope forms an image: objective, infinity space, tube lens and eyepiece, with tube lens lengths by maker and typical NA values.
Micro BCA Assay: Working Range and When to Use It
The micro BCA assay measures dilute protein at 0.5-40 µg/mL. See how it differs from the standard BCA kit in range, time and buffer compatibility.
Red Cell Lysis Buffer Recipe: ACK Components, pH and Commercial Alternatives
Red cell lysis buffer recipe: the ACK components, pH 7.2-7.4, and how home-made, 1X/10X and one-step fix/lyse reagents differ.
Cryopreservation Media: Components, Types and How They Differ
What cryopreservation media contain and how serum, serum-free and premade cell freezing media differ, compared from Gibco and ATCC formulations.
RNA in Agarose Gel: Denaturing vs Nondenaturing and How to Read the Bands
How RNA is run in agarose gels, denaturing versus nondenaturing, and how to read intact, degraded and poly(A) RNA lanes.
Plasmid Design: Choosing a Backbone, Promoter, Marker and Tags
A plasmid design checklist ordered by dependency: host, promoter, selectable marker, insertion site, then tag and reading frame.
Optimum pH for Trypsin: Range, Buffers and Why Activity Drops Off
The optimum pH for trypsin is about 8. Compare quoted ranges, digestion buffer pH values, reversible inactivation at pH 4 and autolysis.
0.5 McFarland Standard: Absorbance, CFU/mL and Preparation Checks
What a 0.5 McFarland turbidity standard is, its absorbance and CFU/mL values, barium sulfate versus latex, and bench checks.
96 Well Plate Volume: Total vs Working Volume per Well
96 well plate volume: total vs working volume per well, with published Corning figures for flat and V-bottom plates.
Phenol-Chloroform Extraction of DNA: How It Works and Its Hazards
How phenol:chloroform extraction of DNA works, what each reagent removes, and a side-by-side of NIOSH and OSHA limits for phenol and chloroform.
Ct Values in qPCR: What the Cycle Threshold Is and What Moves It
What a Ct (Cq) value in qPCR is, why a higher Ct means less template, and the threshold, baseline and reporting factors that change it.
96-Well Plate Dimensions: Footprint, Height and Well Spacing (ANSI/SLAS)
96-well plate dimensions per ANSI/SLAS: 127.76 x 85.48 mm footprint, 14.35 mm height, 9 mm well pitch, and the A1 position, with tolerances.
Percent Solution Dilution Calculator: Formula, Table and Examples
Dilute any percent solution with C1V1 = C2V2: formula, a printable lookup table of mL stock per 100 mL, two worked examples and Excel, R and Python code.
Secondary Antibodies for Western Blot: Host Species, HRP, AP and Fluorescent Labels
How to choose a secondary antibody for western blot: match the primary host species, pick HRP, AP or fluorophore, check cross-adsorption and dilution.
N. meningitidis Gram Stain: What the Smear Shows and What Confirms It
What the N. meningitidis Gram stain shows in CSF, how the smear fits the lab workflow, and which culture, oxidase and sugar tests confirm the organism.
Alpha Hemolysis on a Blood Agar Plate: What the Green Halo Is and How to Read It
Alpha hemolysis on a blood agar plate is a green or brown halo, not true lysis. What causes it, how it differs from beta and gamma, and how to read it.
Potato Dextrose Agar Plate: Composition and Uses
What a potato dextrose agar plate is, its formula, how acidified PDA differs, what it is used for and how to handle it, from two manufacturer sheets.
Ampicillin Working Concentration in LB Broth and Plates
Ampicillin working concentration for LB broth and plates: 100 µg/mL, a worked dilution table from a 100 mg/mL stock, and when to add it.
How to Interpret Western Blot Results: Band Size, Extra Bands and Controls
Read a western blot in order: expected size, direction of any shift, likely causes of extra bands, and the controls that show which band is your protein.
384 Well Plate Volume: Total vs Working Volume Explained
384 well plate volume: total vs working volume, with published figures for standard clear and low-volume 384-well plates.
Origin of Replication in Plasmids (ori): Copy Number and Compatibility
The plasmid origin of replication (ori) sets copy number and compatibility. A sourced table of common origins and a checklist for reading vector descriptions.
Mol to Molarity: Formula, Lookup Table and Worked Examples
Mol to molarity: M = n/V with a mole-volume lookup table, worked examples, and how to get moles from molarity and volume, with Excel, R and Python code.
TaqMan qPCR: How Hydrolysis Probe Assays Work and What to Record
How TaqMan hydrolysis probe qPCR works, which assay format fits which question, and what to record when ordering and reporting probe assays.
Mass Percent Solution: Formula, Worked Examples and How It Differs from w/v
Mass percent solution formula, how to calculate a percent solution by weighing, and how w/w differs from w/v, with the NIST and IUPAC notation advice.
How to Count Colonies on an Agar Plate (and Turn the Count Into CFU/mL)
Count colonies on an agar plate: pick the countable plate, handle spreaders, average replicates and convert to CFU/mL, with FDA and USDA ranges compared.
DMSO Molar Mass: 78.13 g/mol, Formula and Conversions
DMSO molar mass is about 78.13 g/mol (C2H6OS, CAS 67-68-5), with sourced values, density and worked mass-volume-mole conversions.
ISO Class 5: Particle Limits, Class 100 and Grade A
ISO Class 5 allows 3,520 particles/m3 at 0.5 um. See how FDA and EU Annex 1 use it, and how Class 100 and Grade A relate.
Protein Molarity Calculator: mg/mL to µM, Formula and Table
Convert protein mg/mL to micromolar: formula, UniProtKB mass table, two worked examples, Excel/R/Python code and the precursor-mass trap.
Plasmid Vector: What It Is and How It Differs From a Plasmid
A plasmid vector is a lab-engineered plasmid that carries foreign DNA into a cell. Learn how plasmid and vector differ and which elements to check.
What Is an Agar Plate? Types, Media Classes and Storage
An agar plate is a petri dish filled with solid growth medium. Learn the CDC media classes, common plate types and storage basics.
Function of Trypsin: Digestion, Cleavage Specificity, and Laboratory Use
Function of trypsin: how it digests protein, cuts after lysine and arginine, and what to check on research-grade trypsin.
Plasmid Map: How to Read One (Features, Restriction Sites, Sources)
How to read a plasmid map: features, restriction sites, where the sequence comes from, and what to check before relying on the map.
Competent Cells: Chemical vs Electrocompetent and How to Read Efficiency
Competent cells explained: what the term means, chemically versus electrocompetent E. coli, and how to read transformation efficiency (cfu/ug) on a label.
Bacillus subtilis Gram Stain: Gram-Positive Rods, Spores and Why Old Cultures Look Pink
Bacillus subtilis Gram stain: gram-positive rods that can read gram-variable in older cultures, plus how the Gram stain differs from an endospore stain.
Primary and Secondary Antibodies: What Each Does and How to Match Them
Primary antibodies bind the antigen; secondary antibodies target the primary. A sourced checklist for matching host species, subclass and cross-adsorption.
Millimolarity to Molarity: mM to M and µM to M Conversion Table
Convert millimolar (mM) and micromolar (µM) to molar (M): divide mM by 1,000 and µM by 1,000,000. Includes a lookup table, worked examples and Excel, R and Python snippets.
NaOH Molarity: Formula, Grams per Litre Table and Worked Examples
Calculate NaOH molarity from mass and volume, with a grams-per-litre lookup table, worked examples, code snippets and a sourced safety note.
Differential Scanning Calorimetry (DSC): What It Measures and Which Standards Apply
DSC explained: what it measures, and which ASTM method covers the glass transition versus melting and crystallization temperatures.
Haemophilus influenzae Gram Stain: What the Smear Shows
H. influenzae appears as small gram-negative coccobacilli on a Gram stain. See what the smear can and cannot show, and what confirms species and type b.
MALDI-TOF: How It Works, What It Identifies and Where It Fails
MALDI-TOF mass spectrometry explained: how it works, what FDA-cleared systems include, and when a microbial identification can mislead.
What Is a Chiller? Laboratory Recirculating Chillers
A laboratory chiller cools a liquid and pumps it round a closed loop. How it works, what it cools, and how capacity, coolant and siting are set.
Fractional Distillation: How It Works, Column Types and Limits
Fractional distillation separates close-boiling liquids with a fractionating column. Compare Vigreux, steel wool and bead columns, plus azeotrope limits.
Index Hopping: How Reads End Up in the Wrong Sample, and How to Detect It
Index hopping is a low-level cross-contamination artifact in multiplexed NGS runs, most pronounced on patterned flow cells with ExAmp chemistry. Here’s how it happens, how to spot it via unused index combinations in your demultiplexing report, and why unique dual indexing (not combinatorial indexing) is the fix.
Colocalization Analysis in Fiji: Which Plugin, and How to Set the Costes Threshold
A practical walkthrough of running colocalization analysis in Fiji/ImageJ: the Coloc2 plugin, the Costes automatic threshold method and its randomization significance test, and a step-by-step workflow from image prep through interpreting the output scatter plot.
Correlative Light and Electron Microscopy (CLEM) Workflows
How CLEM combines fluorescence-based molecular targeting with EM ultrastructural resolution: the general workflow, fiducial-marker registration, fixation trade-offs, and typical use cases.
FRET Microscopy: Sensitized Emission, Acceptor Photobleaching and Controls
FRET only occurs within about 1-10 nm, making it a molecular-scale proximity sensor. Compare the two intensity-based measurement methods — sensitized emission and acceptor photobleaching — and the donor-only, acceptor-only and negative controls each requires.
Viral Vectors: The Major Types and How Each Delivers a Transgene
How AAV, lentiviral, gammaretroviral, adenoviral and HSV-1 vectors each deliver a transgene — cargo limits, integration versus episomal persistence, serotype tropism, pre-existing antibody thresholds, and the long-term follow-up duration FDA ties to each class.
Solid Phase Microextraction (SPME): Fibre Selection and Sampling Mode
SPME method development turns on two decisions: whether the coating absorbs or adsorbs (which sets your linear range and displacement risk), and whether you sample the headspace or immerse the fibre. A practitioner guide with vendor and peer-reviewed data.
Richardson-Lucy Deconvolution: Iteration Count, Regularisation, and Reading the Artefacts
Richardson-Lucy is provably ill-convergent, so the iteration count is the regularisation parameter rather than a quality setting. How to choose and defend one, when to add total-variation regularisation, and how to identify the five artefacts RL reliably produces.
Differential Gene Expression Analysis: How to Model, Test and Read the Result
A practitioner’s guide to differential gene expression analysis: why the model needs raw counts, how dispersion and fold-change shrinkage work, how to write a design formula that answers your actual question, and how to read every column of the results table — including the NAs.
Super-Resolution Microscopy: Choosing Between SIM, STED and SMLM
A practical decision guide to SIM, STED and single-molecule localization microscopy: what each measured on the same specimen, why labelling density and linkage error — not the instrument — usually cap your resolution, and how to prove the image is not a reconstruction artefact.
Two-Photon Microscopy: Deep-Tissue Imaging Principles and the Limits That Actually Bite
Two-photon microscopy’s depth ceiling is set by near-surface out-of-focus fluorescence, not by available laser power. A practical guide to attenuation lengths, measured depth limits in mouse cortex, heating thresholds, and when to stop pushing and change technique.
Leiden Clustering for Single-Cell Data: How the Algorithm Works and How to Tune It
Leiden partitions a k-nearest-neighbour graph in three phases and, unlike Louvain, guarantees connected communities. But it returns clusters from homogeneous data too. This guide covers the knobs that matter, in order of impact, and how to defend the number of clusters you report.
FRAP (Fluorescence Recovery After Photobleaching): Designing and Interpreting the Experiment
A practical guide to fluorescence recovery after photobleaching: choosing the bleach ROI and bleach depth, normalising the curve, using the effective radius rather than the nominal radius to get a diffusion coefficient, and the artefacts that silently corrupt mobile fractions.
Mass Spectrometry Imaging (MSI): Workflow, Matrix Selection and Annotation Confidence
A practical MSI workflow guide: choosing MALDI, DESI or SIMS by resolution and analyte class, sectioning and matrix application that preserve spatial fidelity, formula-level FDR annotation limits, normalization artifacts, and imzML/MIAMSIE reporting.
Isoelectric Focusing: pI Separation, Ampholytes and IPG Strips
Isoelectric focusing separates proteins at the pH where their net charge is zero. Most failed runs trace to three things: conductivity in the sample, an endpoint measured in hours rather than volt-hours, and a reducing agent that leaves the basic end of the strip.
Expansion Microscopy: Choosing a Protocol and Proving the Expansion Was Isotropic
Expansion microscopy physically enlarges a fixed specimen inside a swellable hydrogel so a conventional confocal resolves nanoscale detail. The protocol choice matters less than measuring the local expansion factor and validating isotropy in the region you actually imaged.
Fluorescence Lifetime Imaging (FLIM): What Lifetime Measures That Intensity Cannot
FLIM measures how long fluorophores stay excited, not how many photons they emit — a readout that is largely concentration-independent. A practical guide to photon budgets, the pile-up limit most people quote wrong, IRF limits, phasor analysis and FLIM-FRET.
Phred Quality Scores: How Q Values Encode Base-Call Error Probability
A Phred quality score is a predicted base-call error probability on a negative log scale, not a measurement. This guide covers the Q-to-accuracy mapping, why arithmetic averaging of Q values is wrong, FASTQ encoding offsets, and modern Q-score binning.
Spatial Proteomics: Methods for Mapping Proteins to Tissue Location
A working comparison of spatial proteomics methods for mapping proteins to tissue location — targeted multiplexed imaging versus discovery mass spectrometry — plus the antibody validation and cell segmentation problems that decide whether the data means anything.
TIRF Microscopy: Penetration Depth, Setup, and What Goes Wrong
TIRF confines excitation to roughly 60-200 nm above the coverslip, but the depth you calculate from theory is not the depth you get. A practical guide to angle, NA, refractive index, illumination uniformity, and single-molecule surface chemistry.
Baculovirus Expression System (BEVS): A Guide to Insect Cell Protein Expression
What the baculovirus expression system (BEVS) is, why researchers choose it over bacterial expression, the recombinant bacmid-to-harvest workflow, and how it compares to mammalian expression systems.
shRNA Knockdown: Mechanism, Design, and Validation
How shRNA silences a target gene via the cell’s RNAi machinery, how it differs from siRNA, how to design constructs that avoid off-target artifacts, and how to confirm knockdown at the mRNA and protein level.
Protein Expression in E. coli: Strain, Vector, and Induction Optimization
How to choose an E. coli expression strain and vector system, and optimize induction temperature, IPTG concentration, and timing for soluble protein yield.
Yeast Two-Hybrid (Y2H) Assay: Principle, Workflow, and Limitations
How the yeast two-hybrid (Y2H) assay detects protein-protein interactions by reconstituting GAL4 transcription-factor activity in yeast: bait/prey plasmid construction, mating/co-transformation, selective-media reporter readout, known false-positive and false-negative failure modes, and how it complements Co-IP for interactome screening versus targeted confirmation.
Laser Capture Microdissection (LCM): Principle, Workflow, and Sample Prep for Molecular Analysis
How laser capture microdissection isolates a pure, spatially-defined cell population from a tissue section for downstream RNA-seq, proteomics, and genomic analysis, plus the workflow steps and degradation/fixation tradeoffs that determine whether it works.
Lentiviral Transduction Protocol: Packaging, Titering, MOI, and Biosafety
How lentiviral transduction works end to end: packaging plasmids and producer cells, titering, polybrene and the transduction step, MOI optimization, selecting transduced cells, and the BSL-2/IBC approval required before you can start.
Luciferase Reporter Assay: Principle, Workflow, and Interpretation
How luciferase reporter assays work: promoter-driven luciferase expression, firefly/Renilla dual-luciferase normalization, the transfection-to-readout workflow, and why reporter activity is a proxy for transcription, not endogenous protein level.
Gene Cloning: From Insert to Verified Construct
The full end-to-end gene cloning workflow: preparing the insert, choosing a vector, restriction-ligation vs. seamless assembly methods, bacterial transformation, colony screening, and sequence verification.
Protein Purification: Strategy, Affinity Tags, and Chromatography Sequence
The general strategy for purifying a protein of interest: cell lysis, clarification, affinity-tag capture (His-tag/Ni-NTA, GST, FLAG), the affinity-ion exchange-size exclusion chromatography sequence, and how to assess purity and yield.
Site-Directed Mutagenesis: Primer Design and Reaction Strategy
Introduce a specific point mutation into an existing plasmid: primers carrying the change, whole-plasmid PCR, DpnI removal of the methylated template, and why colony screening alone isn’t verification.
MTT Assay: Cell Viability Measurement and Pitfalls
A complete guide to the MTT assay for cell viability and cytotoxicity: the tetrazolium-to-formazan mechanism, seeding/incubation/solubilization workflow, absorbance reading, common interference and edge-effect pitfalls, how it differs from hemocytometer counting, and newer alternatives like MTS and CellTiter-Glo.
Northern Blot: RNA Transfer, Probing and Quantification
How Northern blotting sizes and quantifies a specific RNA transcript: denaturing gel electrophoresis, transfer, probe hybridization and stringency, and why it still complements RT-qPCR and RNA-seq.
Electroporation: Parameters, Buffers, and Cell-Type Optimization
A bench-level deep dive into electroporation: the mechanism, voltage/pulse/capacitance parameters, buffer conductivity and ionic composition, why bacteria/cell lines/primary cells need different protocols, and how to troubleshoot over- vs. under-electroporation.
In Situ Hybridization (ISH): Probe Design, Controls, and Readout
In situ hybridization detects a labeled nucleic-acid probe bound to its complementary target inside intact cells or tissue, preserving spatial information extraction-based methods lose.
Co-Immunoprecipitation (Co-IP): Controls, Lysis Conditions and Interpretation
Co-IP vs. standard IP, the non-denaturing lysis conditions that keep complexes intact, the IgG/input/reciprocal controls that make a result credible, and where Co-IP’s sensitivity limits produce false negatives or false positives.
ChIP-seq: Antibody Choice, Controls and Quality Metrics
ChIP-seq maps where a protein binds the genome. The antibody decides data quality, input control is mandatory, and only a spike-in lets you compare global levels between samples.
Southern Blot: Protocol, Stringency and What It Still Answers
Southern blotting separates restriction fragments, immobilises them and finds one with a labelled probe. Depurination, alkaline denaturation and SSC wash stringency decide whether it works.
ATAC-seq: Tagmentation, Quality Control and Failure Modes
ATAC-seq maps open chromatin by Tn5 tagmentation. The practical difficulty is that 20-80% of reads can be mitochondrial, and library quality is decided by TSS enrichment and fragment periodicity.
Gibson Assembly: Mechanism, Overlap Design and Troubleshooting
Gibson assembly joins fragments seamlessly in one tube at 50C. T5 exonuclease makes the overhangs, Phusion fills the gaps, Taq ligase seals the nicks — and overlap Tm decides whether it works.
H&E Staining: Hematoxylin and Eosin Explained
Haematoxylin must be oxidised to haematein and chelated to an aluminium mordant before it stains anything. That, plus differentiation and bluing, explains most H&E results.
Trypsinization: How Trypsin-EDTA Detaches Adherent Cells
Trypsinization is the use of trypsin, formulated with the chelator EDTA, to release adherent cells from their growth surface. This guide covers the biochemistry of the two components, standard working strengths and exposure times, the graded damage of over-trypsinization, how the enzyme is inactivated, and when a gentler dissociation chemistry is the correct choice.
Cell Culture Contamination: Identification, Causes, and Prevention
How to identify bacterial, fungal, yeast, and mycoplasma contamination in cell culture by visual and microscopic signs, what causes each, prevention practices, and when to decontaminate versus discard.
Cell Passaging Protocol: Confluency, Split Ratios, and Scheduling
The full cell passaging workflow: confluency and doubling-time timing, split ratio selection, the adherent/suspension protocol, seeding density, and subculture scheduling.
BCA Protein Assay: Working Reagent, Standard Curve and Calculating Concentration
How to run a BCA protein assay: working reagent mixing ratio, incubation options, standard curve fitting, and calculating protein concentration from A562 absorbance.
Flow Cytometry Compensation: Single-Stain Controls and Matrix Setup
What a single-stain compensation control has to be to be valid, how the compensation matrix is actually calculated from it, and the three errors — wrong control, autofluorescence, and tandem dye degradation — that produce over- or under-compensation.
Western Blot Loading Controls: Housekeeping Protein vs. Total-Protein Normalization
A loading control is only interpretable inside its linear range. How to choose between housekeeping-protein and total-protein normalization, how to run the dilution series that validates either one, and what journals do and do not require.
Western Blot Blocking Buffer: Choosing BSA or Milk by Target
Milk casein is a phosphoprotein that competes with phospho-specific antibodies, and milk biotin saturates streptavidin. BSA avoids both but costs more and is only as clean as its grade. A selection framework by target and detection chemistry.
Western Blot Transfer Buffer: Towbin, Methanol and SDS Decisions
Transfer buffer composition is four decisions – buffering system, methanol, SDS, and the transfer apparatus – made against protein size and membrane. This guide maps each wrong choice to the specific transfer failure it causes, with vendor formulations given in their system and size context.
Massive Transfusion Protocol: Activation, Ratios, and the Lab’s Role
A massive transfusion protocol (MTP) is a predefined process for rapidly releasing large quantities of blood products in fixed ratios to treat life-threatening hemorrhage. This guide covers activation criteria, product ratios, cooler composition, and what the transfusion service/blood bank does at each step.
RNA-seq: Experimental Design Through Analysis
A practical guide to planning an RNA-seq experiment: biological replicates, batch effects, the replicate-versus-depth trade-off, library prep choices, RNA quality thresholds, read depth by application, the analysis pipeline, and GEO/SRA/dbGaP deposition requirements.
Immunofluorescence (IF): Protocol, Controls, and Troubleshooting
A fluorescence-specific IF guide: direct vs indirect labelling, fluorophore selection and spectral bleed-through, autofluorescence and how to suppress it, photobleaching, IF-specific controls, and the IF-vs-IHC decision.
Transfection: Choosing a Method, Optimising It, and the Biosafety Approval You Need
Transfection versus transduction, how to choose between lipid, electroporation and viral delivery, the variables that actually drive efficiency, the controls that make an efficiency figure meaningful, and the IBC registration required before recombinant DNA work begins.
qPCR and RT-qPCR: How They Differ, and How to Run One Properly
RT-PCR, qPCR and RT-qPCR are three different things and RT does not mean real time. What each actually is, dye versus probe chemistry, standard curves and efficiency, reference-gene validation, the controls that matter, MIQE reporting, and troubleshooting by symptom.
SDS-PAGE: How Protein Gel Electrophoresis Works, Gel Selection, and Troubleshooting
A complete guide to SDS-PAGE: the SDS/charge-mass mechanism, the Laemmli stacking-gel system explained, choosing acrylamide percentage by molecular weight, reducing vs non-reducing prep, staining tradeoffs, acrylamide handling safety, and symptom-based troubleshooting.
Sanger Sequencing: Principles, Reading a Trace, and When to Use It vs. NGS
How Sanger (chain-termination) sequencing works, how to read a chromatogram and diagnose double peaks, a symptom-based troubleshooting table, and when to choose Sanger over next-generation sequencing.
Immunohistochemistry (IHC): Protocol, Controls, and Troubleshooting
A complete IHC guide: fixation and antigen retrieval, blocking, detection, the controls that make a result interpretable, antibody validation against the reproducibility problem, and troubleshooting organised by observed symptom.
Restriction Enzyme Digest Setup: Reaction Table, Buffers, and Troubleshooting
A working procedure for setting up a restriction enzyme digest: reaction table and unit definition, solving double-digest buffer compatibility, avoiding star activity, Dam/Dcm methylation sensitivity, and a symptom-by-symptom troubleshooting reference.
Lyophilization (Freeze-Drying): A Complete Process and Troubleshooting Guide
How lyophilization works: freezing, primary and secondary drying, the critical formulation temperatures that govern cycle design, troubleshooting cake defects, excipient roles, residual moisture, scale-up, and core-facility budgeting.
Hemocytometer Cell Counting and Viability: The Complete Guide
A complete, derivation-first guide to manual cell counting with a hemocytometer: chamber geometry, the counting formula explained from first principles, loading technique, the boundary rule, trypan blue viability and its limitations, and when automated counters or flow cytometry are the better choice.
Routes of Administration in Laboratory Rodents: Oral Gavage, IP, SC, and IV
A route-by-route guide to dosing mice and rats: oral gavage restraint and misplacement signs, IP quadrant technique, SC and IV volumes, needle gauge by species, refinement alternatives, and what the IACUC protocol must specify.
Cleanroom Gowning Procedure: Donning, Doffing, and Training
A step-by-step SOP reference for cleanroom gowning: donning and doffing sequence, gowning-room design, qualification/training, and the standards (ISO 14644, EU GMP Annex 1, USP /) that govern it.
Leukoreduction: Process, Purpose, and Blood-Banking Standards
Leukoreduction filters most white blood cells out of red cell and platelet units to reduce febrile transfusion reactions, CMV transmission risk, and HLA alloimmunization. This guide covers the filtration process, pre-storage vs. bedside timing, quality standards, and how it differs from irradiation.
Point-of-Care Testing Coordinator: Responsibilities and Program Structure
What a point-of-care testing coordinator actually does: training, competency assessment, QC oversight, documentation, and how the role fits into CLIA compliance.
Electronic Crossmatch: Eligibility, LIS Validation & AABB/CAP Requirements
What an electronic (computer) crossmatch is, patient eligibility criteria, how blood bank LIS validation must be documented, and how it differs from serologic crossmatch under AABB and CAP requirements.
Specialist in Blood Banking (SBB): Certification Guide for Blood Bank Staffing Compliance
What the ASCP SBB (Specialist in Blood Banking) credential is, how it differs from BB(ASCP) and MLS(ASCP), and how it fits AABB, CLIA, and CAP personnel-qualification requirements for blood bank technical supervisor and reference-lab staffing.
Walking Blood Bank: Emergency Donor Programs for Blood-Supply Contingency Planning
A walking blood bank is a pre-screened roster of on-call donors who give whole blood directly when stored supply runs short. Covers military origins, low titer group O whole blood, civilian disaster-planning use, FDA regulatory requirements, and core SOP elements.
Irradiation of Blood Products: Purpose, Process, and Indications
Irradiation of blood products exposes red cells, platelets, and granulocytes to gamma or X-ray radiation to prevent transfusion-associated graft-versus-host disease (TA-GVHD). This guide covers the mechanism, dose, indications, shelf-life effects, and how it differs from leukoreduction.
Point-of-Care Testing (POCT): Definition, Examples, and How It Differs From Laboratory Testing
Point-of-care testing (POCT) is diagnostic testing performed at or near the patient with results available in minutes. This guide covers the operational definition, common examples, how POCT compares to central laboratory testing, the CLIA regulatory framework, and what a POCT policy and procedure needs to cover.
Reagent Lot-to-Lot Verification: Procedure, Form, and CAP/CLIA Requirements
How to verify a new reagent lot before releasing it for patient testing: the CLIA/CAP regulatory basis, a step-by-step comparison procedure, what belongs on a verification form, and common pitfalls.
What Is IQCP (Individualized Quality Control Plan)? CLIA Requirements Explained
IQCP (Individualized Quality Control Plan) under CLIA: the three required components, who needs one, and how point-of-care analyzer choice shapes it.
Mouse Husbandry: Housing, Care, and Compliance Standards
A practical guide to mouse husbandry for research facilities: housing and environmental standards, feeding, breeding colony management, health monitoring, vendor procurement, and the AWA/PHS Policy/IACUC regulatory framework that governs it.
Zebrafish Husbandry: Water Quality, Housing, Breeding, and Health Surveillance
A practical guide to zebrafish (Danio rerio) husbandry for research facilities: water quality management, housing and stocking density, feeding, breeding and embryo collection, health surveillance, and the IACUC/regulatory oversight framework that applies to vertebrate animal research.
Sentinel Mice: How Rodent Colony Health Monitoring Works
Sentinel mice are exposed to used bedding from a research colony and tested on a fixed schedule so facility staff can detect rodent pathogens before an outbreak affects research validity or animal welfare.
Western Blot No Bands: Troubleshooting Decision Tree
A symptom-first decision tree for western blot failures: no bands, ghost bands, multiple bands, faint bands, smiling bands, and high background, starting from a single Ponceau check.
Phase Contrast Microscopy: Setting Up and Aligning the Phase Rings
A step-by-step procedure for aligning phase contrast microscope rings via Kohler illumination and the phase telescope, plus a Ph1/Ph2/Ph3 matching table and troubleshooting guide.
Size Exclusion Chromatography: Column Selection, Calibration and Molecular Weight Determination
How to calculate Kav from V0, Ve and Vt, build a log(MW) calibration curve, and select an SEC column and resin — with a full worked example and a troubleshooting table.
Building an Analytical Calibration Curve: Linear Range, R-squared and Back-Calculating a Concentration
How to build an analytical calibration curve from a standard set, read slope/intercept/R-squared and residuals, and back-calculate an unknown concentration, with a full worked least-squares example plus internal standard and standard addition methods.
Bradford Protein Assay: Standard Curve, Dilution Series and Calculating Concentration
How to run a Bradford protein assay: BSA standard series, dye reagent ratios, incubation time, and a worked calculation from A595 absorbance to mg/mL protein concentration.
SEM vs TEM: Which Electron Microscope for Which Sample
SEM and TEM answer different questions: SEM images surface topography on bulk samples, TEM images internal ultrastructure on sub-100nm sections at near-atomic resolution. Compare signal, resolution, prep burden, cost and failure modes.
IR Spectroscopy: Functional Group Frequency Table and How to Read a Spectrum
A wavenumber correlation table for O-H, C=O, C-C, C-N and other functional groups, a worked example assigning every major band of a spectrum, and a full KBr pellet / Nujol mull / thin-film / ATR sample-preparation and troubleshooting reference.
Transmission Electron Microscopy: Sample Preparation Workflow and Resolution Limits
A numbered TEM sample preparation workflow (fixation through grid staining), specimen-thickness and resolution tables, alternative prep routes, and a troubleshooting table of real artifacts.
Isotope Ratio Mass Spectrometry: Delta Notation, Reference Standards and Reporting
A guide to isotope ratio mass spectrometry (IRMS) delta notation: the formula, the VPDB/VSMOW/AIR/VCDT reference standards, a worked per mil calculation, dual-inlet vs continuous-flow configurations, and a troubleshooting table of common IRMS failure modes.
Limit of Detection vs Limit of Quantitation: How to Calculate LOD and LOQ
LOD vs LOQ compared directly, with two worked calculations — the blank/calibration-curve standard-deviation method and the signal-to-noise ratio method — on the same shared dataset.
Column Chromatography: Packing the Column, Choosing a Solvent System and Collecting Fractions
A procedural guide to column chromatography: choosing silica mesh size and column dimensions, selecting a solvent system from TLC Rf values, packing a bubble-free bed, loading and eluting, monitoring fractions by TLC, and troubleshooting common failure modes.
Surface Plasmon Resonance (SPR): Running a Binding Assay and Calculating KD from a Sensorgram
A step-by-step SPR binding assay procedure from ligand immobilization through regeneration, plus a worked calculation deriving ka, kd and KD = kd/ka from real sensorgram values, with a troubleshooting table.
Cell Culture Reference Numbers: Vessel Surface Areas, Media Volumes and Seeding Densities
A reference table of flask, plate and dish surface areas, media volumes, dissociation volumes and seeding densities for cell culture, plus a worked scale-up example.
Flow Cytometry: Principles, Panel Design, and Gating Workflow
A complete guide to flow cytometry: fluidics/optics/electronics, FSC/SSC, panel design and staining index, compensation vs. spectral unmixing, FMO vs. isotype controls, a full gating sequence, sample-prep artifacts, sorting biosafety, MIFlowCyt/FlowRepository reporting, and core-facility recharge rates.
Gram Stain: Procedure, Reagents and How to Read the Result
A step-by-step Gram stain protocol with reagent timings, a purple-vs-pink results table, worked organism examples, and the single most common cause of a false-negative result.
LC-MS Explained: How Liquid Chromatography and Mass Spectrometry Are Coupled
How liquid chromatography and mass spectrometry are actually coupled: ionization sources (ESI, APCI, APPI), mass analyzers (quadrupole, TOF, Orbitrap, ion trap), MS/MS and MRM quantitation, matrix effects/ion suppression, and mobile-phase compatibility.
Thin-Layer Chromatography: How to Run a Plate and Calculate Rf
A step-by-step thin-layer chromatography procedure with two fully worked Rf calculations, a solvent-system selection table, and a troubleshooting table for common plate problems.
Auger Electron Spectroscopy (AES): How It Works and What It Measures
How Auger electron spectroscopy generates a surface-elemental signal, why it samples only the top few nanometers, how it compares to XPS, and how researchers typically access it through a core facility.
Powder Diffraction File (PDF): ICDD’s Reference Database for XRD Phase Identification
The Powder Diffraction File (PDF) is the ICDD’s curated reference database of powder X-ray diffraction patterns used to identify crystalline phases by matching measured d-spacings against known entries.
X-Ray Crystallography: How It Works, From Crystal to PDB Deposit
A researcher-facing guide to X-ray crystallography: Bragg’s law and the phase problem, the crystal-to-structure workflow, how to read data-quality metrics like R-free and CC1/2, and why PDB deposition of coordinates and structure factors makes the field self-correcting.
Confocal Microscopy: Principle, Setup, and When to Use It
How confocal microscopy works, when it beats widefield fluorescence, the parameters researchers must set and report, and the sample-prep, artefact, and image-integrity practices behind defensible confocal data.
Cell Culture Basics: A Beginner’s Guide for New Lab Members
A beginner’s guide to mammalian cell culture covering equipment, aseptic technique, media, passaging, cell counting, contamination control, and biosafety for new lab members.
Buffer and Solution Preparation: A Practical Lab Guide
The practical side of buffer preparation: choosing a buffer system, adjusting and verifying pH, sterilizing without degrading the buffer, and storing it correctly.
Cryopreservation of Cells: Basic Protocol and Best Practices
A step-by-step protocol for cryopreserving mammalian cell lines and primary cells: cryoprotectant selection, controlled-rate freezing, liquid nitrogen storage, thawing, and the mistakes that most often reduce post-thaw viability.
How to Write a Lab SOP: Step-by-Step Template and Guide
A practical, step-by-step guide to writing a lab SOP: the standard section structure, how to draft procedure steps that actually get followed, version control, review cadence, and a reusable template outline.
RNA Extraction Protocol Basics: Methods and Step-by-Step Overview
A step-by-step guide to RNA extraction: guanidinium-phenol-chloroform vs. column-based methods, RNase-free technique, DNase treatment, and how to assess RNA purity and integrity (A260/280, A260/230, RIN).
Pipetting Technique: Best Practices for Accuracy and Precision
A calibrated pipette still depends on the person using it. This guide covers the hand technique — tip selection, pre-wetting, immersion depth, aspiration speed, forward vs. reverse pipetting — that determines whether a measurement is actually accurate and precise on the bench.
DNA Extraction Protocol Basics: Methods and Step-by-Step Overview
A practical, method-by-method walkthrough of DNA extraction: the four core steps every protocol shares, when to use organic, salting-out, silica spin-column, magnetic bead, or CTAB extraction, a generic step-by-step workflow, and how to assess yield, purity, and common failure points.
ELISA Protocol Basics: Step-by-Step Overview
A step-by-step ELISA protocol covering plate coating, blocking, antibody incubation, washing, and detection, plus a symptom-to-cause troubleshooting table (high background, no signal, poor curve, edge effects, high CV) with an isolating experiment for each.
PCR Protocol Basics: How to Set Up a PCR Reaction
A step-by-step guide to setting up a standard PCR reaction: reagent components and concentrations, master mix workflow, thermal cycling parameters, primer design basics, and troubleshooting common failure modes.
Agarose Gel Electrophoresis Protocol Basics: What It Is and How It Works
A complete guide to agarose gel electrophoresis: how size separation works, choosing agarose percentage, casting and running a gel, staining safely, extraction and quantification limits, and a symptom-by-symptom troubleshooting reference.
Aseptic Technique in the Lab: Complete Guide (vs. Sterile Technique)
Aseptic technique for cell culture and microbiology: what it is, how it differs from sterile technique, biosafety cabinet vs. laminar flow hood, disinfectant contact times, mycoplasma contamination, and cell-line authentication as a research-integrity safeguard.
Pipette Calibration: How and When to Calibrate Lab Pipettes
What pipette calibration checks, how often to calibrate based on usage and risk, in-house verification vs. accredited calibration services, the ISO 8655 gravimetric method, and what to do when a pipette fails.
Western Blot Protocol Basics: Step-by-Step Walkthrough
A complete step-by-step western blot protocol covering sample preparation, SDS-PAGE, membrane transfer, blocking, antibody incubation, detection, and troubleshooting common failure points.
Micropipette Types and Uses: Single-Channel vs. Multichannel
A practical explainer on micropipette types for lab work: single-channel vs. multichannel, volume-range families, air- vs. positive-displacement, and how to match a pipette to the task.
UV-Vis Spectrophotometer Basics: How It Works and Measures Concentration
How a UV-Vis spectrophotometer measures concentration: the absorbance/Beer-Lambert principle, instrument components, blanking, standard curves, common lab applications (A260/A280/OD600), and the most common measurement errors.
Serial Dilution Technique: How to Perform and Calculate
How to perform and calculate a serial dilution step by step, including the C1V1=C2V2 formula, a worked tenfold dilution series, and back-calculating original concentration from colony counts.
Molarity and Solution Calculations for the Lab
A practical walkthrough of molarity, mass-to-mole conversion, stock solution dilution math (C1V1=C2V2), and serial dilutions for the research lab, with worked examples and common error patterns.
