Quick facts
- A flow cytometer passes cells single file through a beam and counts and sorts them by the light each cell scatters and emits, and an automated differential cell counter applies the same principle to a blood sample.
- In the United States the family is filed under 21 CFR 864.5220, where the automated differential cell counter and the multicolour cytometric analysis system are both Class II, each under its own product code.
- Canada lists no flow cytometer by name. A general laboratory instrument that does not itself carry a diagnostic claim is a non-invasive device, and Rule 7(1) of Schedule 1 to the Medical Devices Regulations places all other non-invasive devices in Class I.
- The contrast is real and it turns on the claim rather than the hardware: the same instrument reads Class II in the United States and Class I in Canada when it is sold as general laboratory equipment.
- A unit that carries a specific diagnostic claim is filed as an in vitro diagnostic device in Canada, so the intended use written on the label decides which regime applies.
- The entries and rule text quoted here were checked against the openFDA device classification API and the Regulations on 2026-10-10.
A flow cytometer is the instrument a laboratory uses when it needs to know not only how many cells are in a sample but what kind they are. It drives a stream of cells past a laser one at a time and reads the light each cell gives off, so a mixed population becomes a set of counts. For a laboratory buying one, two questions matter: what the instrument has to clear before it is sold, and what the counting service needs around it. This article answers the first from both rulebooks and the second from how the count is run.
What is a flow cytometer?
A flow cytometer suspends cells in a fluid and forces them into a narrow stream so that they pass a beam one at a time. Each cell scatters light, and a labelled cell emits fluorescence, so the instrument records a set of measurements per cell. Those measurements separate one population from another, which is how a laboratory counts the types of white cell in a blood sample or checks a cell-surface marker.
An automated differential cell counter is the same idea applied directly to a blood count. It sorts and counts the white cell types that a manual differential once counted by eye, and it reports the percentages a clinician reads. A research or clinical immunology instrument goes further and sorts live cells, which is why the same family covers a routine counter and a multicolour analysis system.
How does the United States classify a flow cytometer?
The United States files the family under one regulation. 21 CFR 864.5220 covers the automated differential cell counter and the related cytometric devices, and every device inside it is Class II, each under its own product code. A Class II entry reaches the market with the controls the regulation attaches to it, and premarket notification applies unless the specific product code is exempt.
| Item | United States | Canada |
|---|---|---|
| Basis of the class | Named entry, 21 CFR 864.5220 | Rule-based, Schedule 1, MDR |
| Class as general lab equipment | Class II | Class I, Rule 7(1) |
| Class with a diagnostic claim | Class II | Filed as an in vitro diagnostic device under the Regulations |
| Why the class | The named entry | Whether the instrument carries a claim |
| Market path for the maker | Premarket notification, unless the product code is exempt | Establishment licence for Class I; a device licence where a diagnostic device rule applies |
| Who may import or sell | Establishment registration | Establishment licence |
The point a buyer should hold on to is that the United States files the instrument by name and by what it is, while Canada lets the intended use draw the line. That is why the same box can be two different classes across the border.
Which devices share the United States entry?
The entry is a family, and reading it closely shows how a laboratory's separate purchases sit inside one rule.
| Device inside 21 CFR 864.5220 | Product code | Class | Where it is used |
|---|---|---|---|
| Automated differential cell counter | GKZ | Class II | Routine blood counts |
| Multicolour fluorescent imaging cytometric analysis system | PMG | Class II | Cell population analysis |
| Flow cytometry calibrator | PDX | Class II | Instrument calibration |
| B lymphocyte marker assay | LJD | Class II | Immunology testing |
Read together, the rows explain why a purchase order should name the device and its code. A request for "a flow cytometer" names a family, and the code is what ties a unit to the filing the manufacturer holds.
How does Canada classify the same instrument?
Canada starts from the intended use. The Regulations classify a device by what it is intended to do, and a general laboratory instrument that measures and sorts cells without itself making a diagnostic claim is a non-invasive device. Rule 7(1) of Schedule 1 places all other non-invasive devices in Class I, so a general-purpose cytometer used for laboratory work sits in the lowest class.
Where the same instrument carries a claim to detect, measure or monitor a specific condition, it is filed as an in vitro diagnostic device under the Regulations, and the class follows the IVD classification rules. Nothing about the optics changes; the label does. A laboratory buying a unit should therefore ask what the manufacturer claims for it, because the answer decides which regime the instrument is sold under in Canada.
Do Canada and the United States use the same laboratory standards?
The technical layer is shared. ISO 15189 sets the quality and competence requirements for medical laboratories, and ISO 13485 sets the quality management system a manufacturer of either market works to. A differential count reported in a Toronto and a Seattle laboratory follows the same international convention for the cell types, so a result can be read across the two, and the difference between the markets is the filing, not the count.
The point where the two rulebooks diverge is not the instrument but the report. The class of a device does not set a reference range, and a laboratory's own reference interval comes from its own validation. A supplier that quotes a normal range is quoting a clinical judgement it does not own.
What does a laboratory check before it buys a cytometer?
The purchasing decision turns on the workload. A laboratory that runs high-volume blood counts buys an automated differential counter for its throughput and its repeatability across the day. A research or immunology laboratory buys for the number of colours it can resolve and for the calibration it can hold. Both check the same two things: the calibration routine, because a drifted instrument reports a wrong proportion, and the fluidics, because a clogged line stops the run.
A laboratory also has to decide what happens to the sample path. The instrument is flushed and cleaned between runs under the laboratory's own procedure, and the cleaning record belongs with the calibration record. Keeping the two together is the simple fix that carries across both countries.
Which laboratory consumables does a counting bench restock?
The instrument is one line on a laboratory order that turns over quickly. A counting bench restocks the sterile centrifuge tubes it uses to hold prepared samples and the leak-proof graduated sample cups it uses for specimen handling. A laboratory that also runs its own steriliser pairs the sterilization monitoring range with the 24-hour monitoring five-pack. Labs 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 864.5220, Automated differential cell counter
- 21 CFR 864.5200, Automated platelet counting instrument
- 21 CFR 864.4010, General purpose reagent
- Medical Devices Regulations, SOR/98-282, full text
- openFDA device classification API
- ISO 15189:2022, medical laboratories
- ISO 13485:2016, medical devices quality management
- ISO 14971:2019, risk management for medical devices
- ISO 15197:2013, in vitro diagnostic test systems
- ISO 17511:2020, metrological traceability of IVD values
- Health Canada, medical devices
- CCOHS, OSH answers
- Public Health Ontario, laboratory services
- CLSI, clinical and laboratory standards
- WHO, Laboratory biosafety manual
- Royal College of Dental Surgeons of Ontario
- Canadian Dental Association
- AACC, laboratory medicine
- eCFR, Title 21, Food and Drugs
- Minnesota Department of Health
A record of when the cytometer was calibrated, and by whom, is the part of a counting bench that is hard to rebuild after the fact. The printable instrument calibration log is a blank form with columns for the instrument, the date and the initials of the person who ran the check. The calibration log generator on the same page sizes the form to the number of instruments a laboratory runs. No account and no sign-up are needed to open either one.
Every laboratory is set up 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
- Microplate Readers in Canada vs the US: Which Class?
- Coagulation Analysers in Canada vs the US: Which Class?
- Blood Gas Analysers in Canada vs the US: Which Class?
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 laboratory belong to the manufacturer and to the requirements that apply to it.
Frequently Asked Questions
Is a flow cytometer a Class II device in the United States?
Yes. The automated differential cell counter is a named Class II entry at 21 CFR 864.5220, and the multicolour cytometric analysis system and the flow cytometry calibrator sit in the same regulation in Class II.
How does Canada classify a flow cytometer?
Canada lists no flow cytometer by name. A general laboratory instrument that does not itself carry a diagnostic claim is a non-invasive device, and Rule 7(1) of Schedule 1 places all other non-invasive devices in Class I.
When does a flow cytometer become an in vitro diagnostic device in Canada?
Where the instrument is intended to detect, measure or monitor a specific condition and carries that claim, it is filed as an in vitro diagnostic device under the Regulations, and the class follows the IVD classification rules.
Why is the same instrument two different classes across the border?
The United States files the instrument by name and reaches Class II, while Canada lets the intended use draw the line, so a unit sold as general laboratory equipment lands in Class I unless it carries a diagnostic claim.
Do Canada and the United States use the same laboratory standards?
Both markets build on the shared ISO layer, including ISO 15189 for medical laboratories and ISO 13485 for quality management, so a differential count follows the same international convention in either country.
Does the device class set a reference range?
No. The class of a device does not set a normal range; a laboratory's reference interval comes from its own validation rather than from the device rule or the supplier.
What should a laboratory record for a cytometer?
Record when the instrument was calibrated and by whom, and keep the cleaning record with the calibration record so the two cannot be separated.
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