Dye and Chemical Stains in Canada vs the US: Which Class Applies?

Quick facts

• A dye or chemical solution stain is a mixture of dyes or non-dye chemicals in solution used to stain cells and tissues for diagnostic histopathology, cytopathology or hematology.
• United States: the stain has a named entry at 21 CFR 864.1850, placed in Class I, exempt from premarket notification subject to the limitations in the section, and exempt from the quality system regulation; the openFDA device classification API lists stains such as Giemsa under product code HYF and the Mallory trichrome stain under HYW.
• Canada: a staining reagent used in diagnosis is an in vitro diagnostic device and reaches Class I through Rule 8 of Part 2 to Schedule 1 of the Medical Devices Regulations, SOR/98-282, which catches every IVDD not caught by the earlier rules.
• Microbiological media are named separately. Part 2 lists microbiological media used to identify or infer the identity of a microorganism at Class I.
• The class turns on the claim, not on the colour: a stain sold to prepare a diagnostic slide is a device, while a dye sold for a non-diagnostic use is a laboratory chemical.
• The entry and rule text below were checked against the current CFR text and the Regulations on 2026-10-08.

A stain in a laboratory is the fluid that makes a cell visible. Gram stain separates bacteria by the structure of their wall, Giemsa and Wright stains show the shape of blood cells, and a trichrome stain brings out tissue structure for a pathologist to read. Each of them is bought as a small bottle of fluid, and each of them is treated as more than a fluid because it is used to produce a diagnostic picture. This article explains what a stain is, how each country files it, and what a laboratory should be able to point at when the bottle is bought and when the lot is used.

What is a dye or chemical solution stain?

The stain is a solution of a dye or a non-dye chemical that binds to a part of a cell and makes it visible under a microscope. Some stains bind to a structure directly, and some work in a sequence where one reagent fixes a colour and a second reveals it. The reagents are chosen so that the colour that appears is reproducible from one slide to the next, and the reproducibility is what makes the stained slide a diagnostic image rather than a picture.

Because the stain produces a diagnostic result, it is not an ordinary laboratory chemical. A bottle of dye sold to a laboratory for diagnostic staining carries a claim, and the claim is what brings it under the device rules.

How does the United States file a stain?

In the United States the stain is reached by a named entry. 21 CFR 864.1850 identifies a dye and chemical solution stain as a mixture of synthetic or natural dyes or nondye chemicals in solution used in staining cells and tissues for diagnostic histopathology, cytopathology or hematology, places it in Class I, exempts it from premarket notification subject to the limitations in the section, and exempts it from the quality system regulation. The openFDA device classification API lists the Giemsa stain under product code HYF, the Mallory trichrome stain under HYW, and the reticulocyte stain under GJH.

Product	Product code	Regulation	Class
Giemsa stain	HYF	864.1850	Class I
Mallory trichrome stain	HYW	864.1850	Class I
Reticulocyte stain	GJH	864.1850	Class I
Glycated hemoglobin assay	GQH	864.7470	Class II

A laboratory that reads a Certificate of Analysis should match it to the entry rather than to the bottle size, because two stains with the same name share the same class but not always the same supplier basis.

Why does Canada reach Class I as an IVDD?

Canada classifies a staining reagent through the in vitro diagnostic device rules in Part 2 to Schedule 1. Rules 1 to 7 reach IVDDs that detect a transmissible agent, that are used for patient management, or that are near-patient devices. A general staining reagent is not caught by those rules, so Rule 8 applies: every other IVDD is classified as Class I. The Part 2 table also names microbiological media used to identify or infer the identity of a microorganism at Class I.

Item	Canada	United States
Named entry	No entry names a stain; it is an IVDD	21 CFR 864.1850
Class	Class I, by Rule 8	Class I
Basis of the class	The IVDD rule that catches all other IVDDs	The named entry the stain is filed under
Microbiological media	Class I under the Part 2 table	Microbiological media entries in part 866
Premarket route	Establishment licence; a Class I IVDD does not get a licence of its own	Exempt from premarket notification
Quality system	The manufacturer keeps the records the Regulations require	Exempt from the quality system regulation

The two countries agree on the class for a general stain and disagree on how they get there: the United States names the product, and Canada names the rule.

What does a laboratory check on the bottle?

The class says how the stain is regulated; the practical questions are about identity and traceability. A staining reagent should arrive with a lot number, a use-by date and the name of the maker, and the laboratory should be able to reconcile the bottle with a record of the lot it opened.

Element	What to check	Why it matters on the bench
Lot number	Printed on the bottle and recorded when opened	A recall can only reach the slides that used the lot
Use-by date	Matched to the working date	An expired stain can change the colour and the reading
Quality basis	A stated test basis, for example ISO 15189:2022 for the laboratory	The reading is only comparable if the basis is known
Storage	The maker’s stated range and light condition	A stain stored out of range is a different reagent
Disposal	The maker’s statement for the chemistry involved	Some stains carry a waste obligation the room has to meet

A laboratory that records the lot when the bottle is opened can answer a recall notice with a list of slides rather than a shrug. That record is the difference between a laboratory that traces a problem and one that replaces a shelf.

What does a laboratory restock around the stain bench?

A staining bench is stocked as a set. The laboratory consumables collection gathers the bench lines a working laboratory draws on, and the sterile 120 mL specimen container carries a specimen to the bench without leaking. Clinics that also monitor their own steriliser pair the sterilization monitoring collection with the 24-hour biological indicator 50-pack. 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

1. 21 CFR 864.1850, dye and chemical solution stains
2. 21 CFR 864.7470, glycated hemoglobin assay
3. openFDA device classification API
4. Medical Devices Regulations, SOR/98-282, full text and Schedule 1
5. Health Canada, medical devices
6. ISO 15189:2022, medical laboratories, requirements for quality and competence
7. ISO 13485:2016, medical devices quality management
8. ISO 14971:2019, risk management of medical devices
9. CLSI, clinical and laboratory standards
10. Public Health Ontario, laboratory services
11. US CDC, laboratory safety
12. US FDA, medical devices
13. World Health Organization, laboratory biosafety manual
14. Standards Council of Canada
15. US OSHA, laboratory safety
16. CCOHS, OSH answers
17. CSA Group
18. College of American Pathologists, laboratory accreditation

Keeping a stain lot record

A slide is only as traceable as the bottle behind it. The printable reagent lot log is a blank sheet with columns for the reagent, the lot number, the date opened, the use-by date and the area of the laboratory, so a recall notice can be matched to the slides that used the lot. The reagent log generator on the same page sizes the sheet to the number of benches a laboratory runs.

Every laboratory and every reagent differs. 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

• Blood agar in Canada vs the US: which media rules
• Culture media, differential and selective, in Canada vs the US: which rules
• Microscope coverslips in Canada vs the US: which specs

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 Gram stain reagent a regulated device?

The class follows the claim. In the United States a dye and chemical solution stain is a Class I device at 21 CFR 864.1850, and in Canada a staining reagent used in diagnosis is an in vitro diagnostic device that reaches Class I through Rule 8 of Part 2 to Schedule 1.

Why does a stain reach Class I rather than a higher class?

A general staining reagent detects no transmissible agent and makes no patient-management claim, so it is not caught by Rules 1 to 7 of Part 2 and falls to Rule 8, which places every other in vitro diagnostic device in Class I.

Which product codes cover a Giemsa or a trichrome stain in the United States?

The openFDA device classification API lists the Giemsa stain under product code HYF and the Mallory trichrome stain under HYW, both under 21 CFR 864.1850 at Class I.

Does a stain need premarket notification in the United States?

The entry places the stain in Class I and exempts it from premarket notification subject to the limitations in the section, and it is also exempt from the quality system regulation.

Where do microbiological media sit in the classification?

In Canada the Part 2 table names microbiological media used to identify or infer the identity of a microorganism at Class I. In the United States the corresponding media are reached through their own entries in part 866 rather than through the stain entry.

What should be recorded when a stain bottle is opened?

The lot number, the date opened and the use-by date should be recorded against the bench or the area, so a recall notice can be matched to the slides that used the lot rather than to the whole laboratory.

Does the class change if the stain is used only for teaching?

The class follows the claim on the product rather than the room it is used in. A dye sold for a non-diagnostic use is a laboratory chemical, while a stain sold to prepare a diagnostic slide carries a diagnostic claim and is filed as a device.