Written and maintained by CASRAI Editorial Board
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General product and use information only; this is not medical advice and not a laboratory procedure.
Short answer
A Cytospin is a cytocentrifuge: a centrifuge that spins a small liquid specimen onto a microscope slide so the cells land as a thin layer in a defined spot. “Cytospin” is the Thermo Scientific brand name; “cytocentrifuge” is the generic term for the instrument class.
Definition and scope
An ordinary laboratory centrifuge sorts material into a pellet in a tube. A cytocentrifuge instead holds a disposable funnel against a slide, so the spin deposits cells directly on the glass. The manufacturer describes the Cytospin name as synonymous with cytocentrifugation since its first launch in 1967 and says it gives thin-layer preparations “from any liquid matrix”, with good results for hypo-cellular fluids such as cerebrospinal fluid and urine (Thermo Scientific Cytospin 4 brochure, checked 2026-11-01). The “over 16,000 laboratories” figure in the same brochure is a manufacturer marketing claim.
How the system is used in practice
The brochure describes the Cytospin 4 as processing twelve specimens at a time, with each specimen in a single-use EZ Cytofunnel assembly that holds a Cytoslide; twelve assemblies fit the head. Speed is programmable from 200 to 2000 rpm, run time from 1 to 99 minutes, and up to 23 programs can be stored. Three acceleration controls are provided for fragile samples. The instrument runs only with the lid locked, alarms for out-of-balance, out-of-tolerance speed and unlocked lid, and has a sealed, autoclavable head. The manufacturer states it meets the IEC 61010 centrifuge safety standards. A specimen safety alarm reminds users at one-minute intervals to remove specimens, which the manufacturer says protects them from air-drying. For the speed-versus-force relationship common to all centrifuges, see RCF vs. RPM.
Funnel, filter card and slide: how the consumables differ
The consumables, not the motor, decide how much specimen a run can take and how large the cell area on the slide is. Every figure below comes from the same manufacturer brochure.
| Consumable | Stated sample volume | Cell deposition area | Other stated feature |
|---|---|---|---|
| EZ Cytofunnel, white filter card | Up to 0.5 ml | 6 mm diameter (28 mm²) | High-absorbency card |
| EZ Cytofunnel, brown filter card | Up to 0.4 ml | 6 mm diameter (28 mm²) | Slower-absorbency card |
| EZ Double Cytofunnel | Not stated per area in the brochure | Two deposition areas on one slide | Doubles the number of presentations per run; pre-attached filter card |
| EZ Megafunnel | Up to 6 ml | 22 × 14.75 mm (325 mm²) | Prepares air-dried and fixed preparations; supplied with Megafunnel Cytoslides |
Cytoslides are 75 × 25 mm optical glass, with a white 12 mm circle marking where cells are displayed on single-circle versions. Single, double and mask (for immunofluorescence) slide formats are listed, and the double slide is designed for use with the Double Cytofunnel.
Where it matters for labs, clinics and supply decisions
A cytocentrifuge is specified and stocked as a set. The brochure’s own specification points give a checklist of what a lab or procurement team needs to name together:
- Instrument and head capacity (twelve positions on the Cytospin 4).
- Funnel type: single, double or Megafunnel, which sets the volume per specimen and the deposition area.
- Filter card colour for single funnels (white up to 0.5 ml, brown up to 0.4 ml).
- Slide format that matches the funnel (single, double, mask) and whether coated or uncoated slides are listed.
- Programmable speed (200-2000 rpm), time and acceleration settings, held as stored programs.
- Safety features: lid lock, balance and speed alarms, autoclavable head, IEC 61010 claim.
- Specimen labelling and traceability, which sits outside the instrument; see specimen labeling error prevention.
Rotor loading and balance rules are covered in centrifuge rotor balancing, and general instrument selection in how to choose a centrifuge. Body-fluid cell analysis is the subject of the CLSI guideline H56, Body Fluid Analysis for Cellular Composition (first edition, 10 July 2006), which covers collecting, processing, examining, storing and reporting results for cerebrospinal, serous, bronchoalveolar and synovial fluids. CLSI lists it as archived, no longer under its consensus revision process, while remaining technically valid and FDA-recognized (CLSI product page, checked 2026-11-01).
Common misunderstandings
- “Cytospin and cytocentrifuge are different machines.” Cytospin is one manufacturer’s brand of cytocentrifuge; the manufacturer itself ties the name to the method.
- “It is a tube centrifuge with a slide adapter.” Per the brochure, the system is built around single-use funnel assemblies that hold a slide, a different arrangement from a pelleting spin.
- “The standard tells you the settings.” CLSI’s H56 description does not mention cytocentrifuge speeds or times. Settings are programmed on the instrument; the manufacturer documents the available ranges, not a universal setting.
- “One funnel suits every specimen volume.” The brochure’s stated volume limits differ from 0.4 ml to 6 ml across funnel types.
FAQ
What is a Cytospin?
Cytospin is Thermo Scientific’s brand of cytocentrifuge, an instrument that spins a small liquid specimen onto a microscope slide so cells form a thin layer in a defined spot (Thermo Scientific brochure).
Is a cytocentrifuge the same as a normal centrifuge?
No. A standard centrifuge pellets material in a tube, while a cytocentrifuge holds a single-use funnel against a slide so the cells are deposited directly on the glass.
What sample volumes do the funnels take?
The manufacturer states up to 0.5 ml for white filter cards, up to 0.4 ml for brown filter cards and up to 6 ml for the EZ Megafunnel.
Does a standard set the cytocentrifuge speed and time?
CLSI H56 is the guideline for body-fluid cellular analysis, but its product description does not give cytocentrifuge settings; the Cytospin 4 provides a programmable range of 200 to 2000 rpm and 1 to 99 minutes.
Sources
- Thermo Fisher Scientific, Cytospin 4 Cytocentrifuge and Cytology Solutions brochure (PDF, 2017), hosted by The Rockefeller University: Cytospin 4 brochure. Checked 2026-11-01. Manufacturer document; figures are the manufacturer’s statements.
- Clinical and Laboratory Standards Institute, H56, Body Fluid Analysis for Cellular Composition. Checked 2026-11-01.
