Quick facts
- A hemocytometer is a named Class I entry in the United States at 21 CFR 864.6160, the manual blood cell counting device, under product code GHO.
- The US entry is exempt from premarket notification subject to the limits in 21 CFR 864.9, so the counting chamber reaches the market without a 510(k) review.
- Canada names no hemocytometer. A counting chamber that is not caught by the patient-management or diagnostic rules falls to Rule 8 of the Medical Devices Regulations, which puts all other in vitro diagnostic devices in Class I.
- A manual counting device is Class I on both sides of the border, but it is not the same as an automated cell counter, which is a separate Class II entry at 21 CFR 864.5200.
- The distinction between manual and automated is where most of the confusion sits, because the two are neighbours in the same rulebook.
- The regulation text quoted here is current to 2026-09-21 and was last amended on 2026-06-17.
A hemocytometer is a thick glass slide with a ruled counting chamber and a cover glass. A technician loads a measured volume of diluted sample, counts the cells under a microscope, and multiplies to get a concentration. It is the oldest way to count cells and it is still the reference method for manual counts. Its class in both countries is low, and the reason is that it counts rather than diagnoses by itself.
What is a manual blood cell counting device?
The United States describes the device in its own words. Under 21 CFR 864.6160, a manual blood cell counting device is a device used to count red blood cells, white blood cells, or blood platelets.
One thing in that sentence matters. The device counts; it does not interpret. It gives a number of cells in a known volume, and the clinical judgement that follows belongs to the laboratory and the clinician. That is why the manual counting chamber sits in Class I while an automated instrument that dilutes, counts and reports a result sits one class higher.
The neighbouring entry is instructive. An automated cell counter is a separate device at 21 CFR 864.5200, and the automated differential counter is another at 21 CFR 864.5220. A buyer who assumes every counting device is one class is treating three entries as one.
How do Canada and the United States classify a hemocytometer?
The counting chamber is Class I in both countries, from two different directions.
| Item | Canada | United States |
|---|---|---|
| Manual counting chamber | Class I by Rule 8 | Class I, 21 CFR 864.6160 |
| Basis named in the rulebook | Whether rules 1 to 7 apply | A named entry and product code (GHO) |
| What decides the class | That the device does not fall into a higher diagnostic rule | Which named entry it is filed under |
| Automated cell counter | Depends on the diagnostic rule it meets | Class II, 21 CFR 864.5200 |
| US premarket route | Not applicable | Exempt from 510(k) subject to 864.9 |
In the United States the counting chamber is a named entry exempt from premarket notification subject to section 864.9. In Canada the hemocytometer is an in vitro diagnostic device used on specimens taken from the body, but it is not a device that is itself used for patient management or diagnosis in the sense the higher rules mean. The Part 2 rules step through transmissible agents, patient management, diagnosis and blood grouping; a manual counting chamber does not meet those descriptions, so it falls to Rule 8, and Rule 8 puts all other in vitro diagnostic devices in Class I.
That is the part that catches people out. Class I does not mean unregulated; it means the device cannot, on its own, drive a clinical decision that would harm a patient if it were wrong.
Why does manual counting stay in Class I while automated counting rises?
Because the Canadian rules classify by the role the device plays, not by the number on the box.
The Part 2 rules in Schedule 1 take a device used for patient management and put it in Class II under Rule 3, and a device used for diagnosis and put it in Class II under Rule 4, lifting either to Class III where a wrong result would be dangerous or where the device is used for cancer screening or staging. A hemocytometer does not produce a managed result on its own; it produces a cell count that a trained person reads. It therefore does not meet rules 1 to 7, and Rule 8 catches it. An automated analyser that dilutes, counts and reports a result, and that a clinician acts on, is described differently and meets a higher rule.
The design rule is easy to state: read whether the device reports a result that drives care, then read the catch-all. Two products that both count cells can sit in different classes if one reads out a number to be interpreted and the other issues a result to be acted on.
Which licence and records differ between Canada and the United States?
For a supplier the class is not a label; it decides which paperwork has to exist before the device can be sold.
In the United States the manual counting chamber is a Class I entry exempt from premarket notification subject to section 864.9. In Canada a Class I device is not licensed device by device; the manufacturer holds an establishment licence under section 45 of the Regulations and keeps the records the Regulations require. A Class II or higher device needs a medical device licence under section 32 supported by a quality-system certificate against ISO 13485. The hemocytometer therefore sits on the lighter Canadian tier, while the automated analyser beside it does not.
What do the two rulebooks actually say?
The two texts are short, and the difference between them is the whole point of this article.
| Rule or entry | Verbatim wording | Effect on a hemocytometer |
|---|---|---|
| Rule 4, Canada | IVDD … intended to be used in diagnosis or patient management is classified as Class II | Does not apply to a manual counting chamber on its own |
| Rule 8, Canada | If rules 1 to 7 do not apply, all other IVDDs are classified as Class I | Class I |
| Rule 9, Canada | an IVDD set out in the table … is classified as the class set out in column 2 | Microbiological media are Class I |
| Rule 7, Canada | In cases where an IVDD … is intended to be used with another IVDD, the class of both IVDDs will be that of the IVDD in the class representing the higher risk | Relevant where the chamber feeds a higher-class system |
| 21 CFR 864.6160, US | Manual blood cell counting device | Named Class I entry, product code GHO |
Read together, the five lines explain why a supplier cannot move the class by relabelling. An automated analyser described as a counting chamber, while it reports a managed result, is described against the text, not against the product.
Which consumables does a manual counting bench restock?
A bench that runs manual counts runs on the same supplies as any other laboratory station. The graduated 90 mL specimen cups carry the sample to the bench, the sterile 15 mL centrifuge tubes hold the dilution, and the double-tipped cotton swabs handle the transfer and the cover glass seat. A clinic that also monitors its own steriliser pairs the sterilization monitoring collection with the 24-hour monitoring five-pack trial. Laboratories and multi-site groups ordering at case level use the wholesale ordering page, and the B2B wholesale collection lists the lines held for institutional buyers. Reselling? become a distributor.
Sources
- 21 CFR 864.6160, Manual blood cell counting device
- 21 CFR 864.5200, Automated cell counter
- 21 CFR 864.5220, Automated differential cell counter
- 21 CFR 864.5240, Automated blood cell diluting apparatus
- Medical Devices Regulations, SOR/98-282, full text
- openFDA device classification API
- ISO 15189:2022, medical laboratories, requirements for quality and competence
- ISO 13485:2016, medical devices quality management
- ISO 14971:2019, risk management for medical devices
- CLSI, clinical and laboratory standards
- Public Health Ontario, laboratory services test index
- CCOHS, OSH answers
- Government of Canada, medical devices guidance
- Standards Council of Canada
- Canadian Dental Association
- Royal College of Dental Surgeons of Ontario
- College of Optometrists of Ontario, standards of practice
- Opto, eye health library
- American Academy of Ophthalmology, eye health
- 21 CFR 864.6400, Hematocrit measuring device
A manual count that is written down the same way every time is a count that can be repeated by the next shift. The printable manual cell count worksheet is a blank sheet with columns for the chamber, the dilution, the squares counted and the calculated concentration, so a discrepancy is visible on the day. The count worksheet generator on the same page sizes the sheet to the number of chambers a bench runs. No account and no sign-up are needed to open either one.
Every counting bench is laid out differently. Ask a compliance specialist and you will get a written answer specific to your equipment and province, with the regulation or standard it is based on cited.
Related reading
- Laboratory Centrifuges in Canada vs the US: Which Class Applies?
- Microcentrifuge Tubes in Canada vs the US: Which Standards?
- Capillary Tubes in Canada vs the US: Which Size and Standard?
CliniEco Medical supplies eye care, laboratory and dental consumables of the kind described in this article. MDEL #35334. This article is written for optometry, laboratory and procurement professionals and is not legal advice; the class of a device and the records kept by a clinic belong to the manufacturer and to the requirements that apply to it.
Frequently Asked Questions
Is a hemocytometer a Class I device in the United States?
Yes. A manual blood cell counting device is a named Class I entry at 21 CFR 864.6160, filed under product code GHO and exempt from premarket notification subject to section 864.9.
How does Canada classify the same counting chamber?
Canada names no hemocytometer. Used on specimens taken from the body it is an in vitro diagnostic device, and because it does not meet the higher patient-management or diagnostic rules it falls to Rule 8, which puts all other in vitro diagnostic devices in Class I.
Is an automated cell counter in the same class?
No. An automated cell counter is a separate Class II entry at 21 CFR 864.5200, and an automated differential cell counter is at 21 CFR 864.5220. The manual counting chamber is the Class I device.
Why does manual counting stay in Class I in Canada?
Because a hemocytometer produces a cell count that a trained person reads, rather than a managed result that drives care by itself. That keeps it outside the higher rules, so Rule 8 applies.
What does the class change for a supplier?
A Class I device sold in Canada sits under an establishment licence and records rather than a device licence. A Class II device needs a device licence under section 32 supported by a quality-system certificate against ISO 13485.
Does a hemocytometer need a 510(k) in the United States?
No. The entry at 21 CFR 864.6160 is exempt from premarket notification subject to the limitations in section 864.9.
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