C Elegans CGC: Strain Ordering & Lab Guide

Short answer

The Caenorhabditis Genetics Center (CGC) is the central international repository at the University of Minnesota, supported by NIH ORIP grant P40 OD010440. It curates and distributes Caenorhabditis elegans mutants, wild isolates, balancers, and bacterial food stocks to academic, non-profit, and corporate laboratories under an NIH cost-recovery fee schedule.

Definition and scope

The Caenorhabditis Genetics Center (commonly referenced as the c elegans cgc or cgc c elegans repository) serves as the primary genetic stock center for the nematode research community. Operating since 1978 and based at the University of Minnesota, Twin Cities, the center is supported by the National Institutes of Health (NIH) Office of Research Infrastructure Programs (ORIP).

The operational scope of the CGC covers three main functions:

• Strain curation and cryopreservation: Maintaining over 20,000 characterized nematode stocks in liquid nitrogen to prevent genetic drift and suppressor accumulation.
• Community distribution: Shipping live worm cultures and bacterial food stocks, primarily Escherichia coli OP50, to registered investigators globally.
• Nomenclature coordination: Partnering with WormBase to standardize strain designations, laboratory codes, and allele names following rules codified by Brenner and Horvitz.

In biomedical research, C. elegans is a primary model for genetics, neurobiology, and aging. Much like repository frameworks described in our Drosophila research resources guide and comparative databases evaluated in the model organism genomic databases comparison, the CGC establishes community-wide genetic traceability.

How it works or how it is used in practice

Acquiring strains through the Caenorhabditis Genetics Center involves three standardized operational phases:

1. Laboratory Account Registration

Orders must be submitted through the official portal (cgc.umn.edu). Accounts require:

• PI-only registration: CGC Lab Codes are assigned exclusively to Principal Investigators (PIs). Laboratory personnel order under their PI’s account.
• Institutional addresses: Deliveries are restricted to recognized academic, clinical, or corporate facilities; shipments to residential addresses are prohibited.
• Identifier portability: A PI’s lab code remains associated with that investigator if they transfer to another institution.

2. Fee Schedules and Payment Pathways

Under its NIH-mandated cost-recovery program, the CGC charges standard fees:

• Annual account fee: A $30 fee charged to each lab on its first order during a 12-month billing period.
• Academic and non-profit rate: $10.00 per strain (covering nematode strains or OP50 bacteria).
• Commercial rate: $150.00 per strain for commercial organizations. Certain strains carry commercial distribution restrictions.
• International processing surcharge: A flat $1.00 per strain added to international orders at checkout.
• Payment rails: Online credit card processing via Authorize.net or institutional Purchase Orders (POs).
• Hardship waivers: Unfunded academic labs and educators can email [email protected] before ordering to request fee waivers.

3. Strain Transit and Bench Handling

Strains are shipped on small Nematode Growth Medium (NGM) agar plates in padded envelopes via standard USPS (or recipient-billed couriers like FedEx, UPS, or DHL). Handling protocols include:

• Starvation conditioning: Worms are starved before shipment to induce stress-tolerant dauer larvae capable of enduring transit conditions.
• Culture recovery: Upon delivery, personnel inspect plates and transfer worms to fresh NGM plates seeded with E. coli OP50. If animals appear immobile, flame-sterilized scalpels chunk agar slices face down onto new seeded plates so burrowed worms emerge.
• Decontamination: Fungal mold is cleared by serially transferring worms across clean plates. Bacterial or yeast contamination is resolved using alkaline hypochlorite solution (bleaching) to recover sterile eggs.

Types or related concepts

The CGC repository curates several biological stock categories, summarized below:

Stock Category	Genetic & Biological Features	Representative Strains	Primary Application
Wild-Type Reference	Canonical unmutated genetic backgrounds	N2 (Bristol), CB4856 (Hawaiian)	Phenotypic baseline controls and QTL mapping
Loss-of-Function Mutants	Single-gene knockouts, deletions, and point alleles	CB189 (unc-32(e189)), MT1406 (lin-12(n676))	Functional genetics and signaling pathway dissection
Chromosomal Balancers	Translocations and marked lethal balancers	mIn1, hT2, nT1 [qIs51]	Maintaining lethal or sterile mutations stably
Reporters & Tagged Loci	Integrated GFP/mCherry or degron-tagged arrays	Endogenously tagged CRISPR lines	In vivo imaging and protein degradation assays
Bacterial Food Strains	Monoxenic bacterial feeder cultures	E. coli OP50, HT115(DE3)	Daily worm propagation and feeding RNAi

Working with the CGC requires understanding community genetic nomenclature codified by Brenner (1974) and Horvitz et al. (1979):

• Lab Code: 2-3 uppercase letters identifying the originating lab (e.g., CB for Cambridge; MT for Horvitz lab). CGC assigns numeric customer codes; alphabetic allele prefixes are registered through WormBase.
• Strain Designation: Non-italicized uppercase lab code plus an integer (e.g., GS60, CB4856) denoting the physical culture and genetic background.
• Gene Symbol: 3-4 lowercase italicized letters, hyphen, and number (e.g., unc-32, lin-12).
• Allele Designation: Lowercase italicized lab code and number in parentheses following the gene (e.g., unc-32(e189)). Revertants concatenate numbers, such as lin-12(n676n930).

Where it matters for labs, clinics or supply decisions

Procuring strains through the CGC impacts experimental reproducibility, consumable stocking, and compliance:

• Genetic quality control: Sourcing authenticated stocks from the CGC prevents uncharacterized background mutations from informal lab exchanges.
• Media and sterilization: Laboratories must prepare NGM agar plates in advance using validated autoclave sterilization protocols.
• Handling consumables: Routine culture maintenance requires sterile transfer pipettes, worm picks, and spatulas for chunking.
• Cross-border compliance: International shipments of living modified strains must comply with import rules aligned with frameworks like the Cartagena Protocol on Biosafety. Strains cannot be redistributed outside the recipient institution without written consent, and publications must cite NIH grant P40 OD010440.

Common misunderstandings

Common operational misunderstandings regarding the CGC include:

• Bulk quantity provision: The CGC provides single starter plates, not bulk quantities; labs must expand and freeze their own working stocks.
• Apparent non-motility: Shipped worms are starved and often dormant dauers; chunking agar onto seeded plates recovers viable populations.
• Personal ordering: Accounts require institutional billing addresses and are restricted to Principal Investigators; residential orders are rejected.
• Customs replacement guarantees: The CGC does not offer free replacements for shipping or customs delays; recipients must track packages actively.
• Unrestricted redistribution: CGC strains cannot be shared with external laboratories without written consent; collaborators must register separate accounts.

FAQ

How do researchers register an account and order strains from the CGC?

Principal Investigators submit a lab code request through cgc.umn.edu/laboratory/request with institutional billing details. Upon approval, laboratory members log in, select strains, and complete payment via credit card or institutional Purchase Order.

What are the fees for ordering C. elegans strains from the CGC?

Under the NIH cost-recovery mandate, laboratories pay a $30 annual account fee on their first order of the year. Academic and non-profit labs pay $10.00 per strain (worms or bacteria). Commercial companies pay $150.00 per strain. International shipments incur an added $1.00 per strain surcharge.

How does the CGC strain and allele naming system work?

The system distinguishes strains from mutations. A strain designation (e.g., GS60) uses uppercase non-italicized letters and numbers to identify the physical line. Alleles appear in lowercase italics within parentheses after the gene symbol (e.g., unc-32(e189)), denoting the lab that generated the mutation.

How should live C. elegans shipments be handled upon arrival?

Inspect plates upon arrival. Because shipments are pre-starved to promote survival, worms may appear dormant. Bench personnel should chunk the agar onto fresh NGM plates seeded with E. coli OP50 and incubate at 20°C to allow worms to resume active feeding and reproduction.

Sources

• Caenorhabditis Genetics Center (CGC). (2026). Frequently Asked Questions. University of Minnesota. Retrieved November 10, 2026, from https://cgc.umn.edu/faq
• Caenorhabditis Genetics Center (CGC). (2026). Conditions of Use and Redistribution Policies. University of Minnesota. Retrieved November 10, 2026, from https://cgc.umn.edu/conditions-of-use
• Caenorhabditis Genetics Center (CGC). (2026). Acknowledging the CGC and NIH Grant Support. University of Minnesota. Retrieved November 10, 2026, from https://cgc.umn.edu/acknowledging-the-cgc
• Caenorhabditis Genetics Center (CGC). (2026). Nomenclature Guidelines and Laboratory Designations. University of Minnesota. Retrieved November 10, 2026, from https://cgc.umn.edu/nomenclature
• Stiernagle, T. (2006). Maintenance of C. elegans. WormBook, The Online Review of C. elegans Biology. Retrieved November 10, 2026, from http://www.wormbook.org/chapters/www_strainmaintain/strainmaintain.html
• National Institutes of Health (NIH) Office of Research Infrastructure Programs (ORIP). (2026). Caenorhabditis Genetics Center Resource Overview (P40 OD010440). Retrieved November 10, 2026, from https://orip.nih.gov/