Quick facts
- A microtome cuts the thin, uniform sections that a histology laboratory mounts on a slide; the rotary, sliding and cryostat forms all do the same job with a different cutting action.
- United States: it is reached as tissue processing equipment at 21 CFR 864.3010, placed in Class I, and the openFDA classification API lists the sliding, rotary and cryostat forms under product codes KFL, IDO and IDP.
- Canada: no entry names a microtome. A non-invasive laboratory instrument is classified by rule, and Rule 7(1) of Schedule 1 to the Medical Devices Regulations, SOR/98-282 puts all other non-invasive devices in Class I.
- Rule 7(2) lifts that device to Class II when it is meant to act as a calibrator, tester or quality-control support to another device, or to be connected to an active device already in Class II, III or IV.
- The two countries land on the same class for the instrument and reach it in two different ways: the United States by a named entry, Canada by the non-invasive rule.
- The entry and rule text below were checked against the current CFR and the Regulations on 2026-10-09.
A microtome is the point in the histology chain where the section thickness is fixed, and it is a clean example of how each country files a laboratory instrument that never touches a patient. This article sets out what the instrument is, how each country reaches its class, and what a laboratory or a buyer should be able to point at when a microtome and its blades are ordered.
What is a microtome?
The instrument advances a trimmed block of embedded tissue past a blade by a set number of micrometres on each stroke, so that every section is the same thickness. A rotary microtome turns a handwheel, a sliding microtome moves the block on a track, and a cryostat cuts frozen sections inside a cooled chamber.
The fact that decides the classification is that the instrument processes a specimen rather than contacting a patient. It is a non-invasive laboratory device, it carries no imaging function and no patient contact, and that combination is what both countries act on when they file it.
How does the United States file a microtome?
In the United States the instrument is reached as tissue processing equipment. 21 CFR 864.3010 covers "Tissue processing equipment" and places it in Class I. The openFDA classification database lists the forms of the instrument under product codes such as KFL for a sliding microtome, IDO for a rotary microtome and IDP for a cryostat.
A Class I device of this kind reaches the market under general controls rather than under premarket approval. The named entry groups the microtome with the rest of the tissue-processing bench — the embedding station, the paraffin oven and the flotation bath — so a laboratory buying the whole chain is buying against one entry and one class.
How does Canada classify a microtome?
Canada does not keep a named entry for a microtome in its classification rules. Instead, Schedule 1 to the Medical Devices Regulations, SOR/98-282, classifies a device by how it meets the body, and a microtome is a non-invasive instrument that the rules do not otherwise name. Rule 7(1) reads: "Subject to subrule (2), all other non-invasive devices are classified as Class I."
The hooks that can move the class are in Rule 7(2): a non-invasive device is classified as Class II if it is intended "(a) to act as a calibrator, tester or quality control support to another medical device; or (b) to be connected to an active device that is classified as Class II, III or IV." A standalone microtome does neither, so it stays in Class I and reaches the market through a device licence under section 32 of the Regulations. The distinction matters when the microtome is sold as a component of a larger automated system: if the system is an active device in Class II or above and the microtome is meant to be connected to it, the hook in 7(2)(b) can lift the class.
| Item | Canada | United States |
|---|---|---|
| Named entry | None; classified by rule | 21 CFR 864.3010 |
| Class | Class I by Rule 7(1) | Class I |
| Basis of the class | The rule that fits a non-invasive instrument | The named entry the instrument is filed under |
| Product code | Not applicable | KFL, IDO, IDP (by form) |
| Class-lifting hook | Rule 7(2): calibrator/tester, or connected to a Class II–IV active device | Special controls if the FDA names one |
| Premarket route | Device licence under section 32 for a Class I device | General controls |
| Quality system | CAN/CSA-ISO 13485 certificate behind the licence | Quality system regulation |
The two countries agree on the class for the same physical reason and reach it in two different ways. A laboratory that orders a microtome against a Canadian purchase order should expect the file behind it to carry a licence number and a quality-management certificate, because those are the records the Regulations attach to a licensed device whatever the instrument is called.
Which standards sit behind the instrument?
The class says how the instrument is regulated; the standards say how it has to behave. ISO 15189:2022 is the competence-and-quality standard that a medical laboratory is assessed against, and a microtome is part of the equipment the laboratory has to control under it. ISO 13485:2016 is the quality-management basis behind the licence, and ISO 14971:2019 is the risk-management basis behind the design file.
| Element | What it covers | Why it matters at the bench |
|---|---|---|
| Section thickness | The advance per stroke, in micrometres | A drifting thickness ruins a special stain |
| Blade clamp | The angle and the locking force | A loose clamp chatters and tears the section |
| Cooling (cryostat) | The chamber set point | A warm chamber softens a frozen block |
| Knife guard | The shield over the blade | The cutting point is the injury risk on the bench |
| Markings | Model and serial legibility | Faded markings force a re-identification |
| Traceability | Maker, model and serial number | An instrument cannot be reconciled to a licence without them |
An instrument that arrives without a maker, a model designation and a serial number cannot be reconciled with a licence, and it should not be accepted into a laboratory.
What should a buyer check with an order?
A microtome bought on a Canadian purchase order and the same instrument bought in the United States are the same physical article with two rule paths behind them. The ways to reconcile them are the same on both sides of the border: a maker, a model designation, a serial number and the instructions for use, together with the section-thickness range the block advance is checked against. A buyer who asks for those fields is asking for the traceability the device rules require, whatever the instrument is called.
The one place the two markets part is the wording. A Canadian laboratory should expect the file to identify the article by the rule that classified it, while a buyer in the United States should expect it to read as tissue processing equipment against a product code. Neither file is wrong; each is answering the question its own market asked.
What else sits beside the microtome?
A histology bench is stocked as a system rather than as a single instrument. A laboratory consumables pack of film and pipettes sits with the bench for the small sealing and transfer steps, and sterile 100 x 15 mm polystyrene petri dishes are kept for the microbiology side of the same laboratory. Laboratories that also reprocess instruments pair the bench with the sterilization monitoring collection for their own load records. 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 864.3010, Tissue processing equipment
- ISO 15189:2022, medical laboratories
- ISO 13485:2016, quality management
- ISO 14971:2019, risk management
- Health Canada, medical devices
- Public Health Ontario laboratory services
- CCOHS, OSH answers
- WHO laboratory biosafety manual
- CCDA, Canadian dental association
- RCDSO standards and guidelines
- Electronic Code of Federal Regulations, Title 21
- US FDA, device classification database (cfPCD)
- US FDA, 510(k) premarket notification database (cfPMN)
- US FDA, device registration and listing (cfRL)
- openFDA device classification API
A laboratory bench is audited on paper as often as it is audited on the shelf. The printable equipment and maintenance log centre carries a blank sheet with columns for the instrument, its serial number, the check performed and the date, so a laboratory can reconcile the microtome it uses with the record it keeps.
The log sheet generator on the same page sizes the sheet to the number of cutting stations a laboratory runs, so a single-microtome room and a multi-bench laboratory print the same form at two different volumes.
Every laboratory and every instrument 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
- Histology cassettes and microtome blades in Canada vs the US
- Paraffin wax in Canada vs the US: histology grades
- Microscope slides in Canada vs the US: which size and finish
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 practice belong to the manufacturer and to the requirements that apply to it.
Frequently Asked Questions
Is a microtome a medical device?
Yes, in both countries. It prepares the sections that a laboratory reads in diagnosis, so it is a device; in Canada it is a non-invasive device classified under Rule 7(1), and in the United States it is reached as tissue processing equipment at 21 CFR 864.3010.
What class is a microtome in the United States?
It is Class I at 21 CFR 864.3010 under the tissue processing equipment entry, with the sliding, rotary and cryostat forms listed under product codes such as KFL, IDO and IDP. It reaches the market under general controls.
Does Canada class a microtome as Class I or Class II?
A standalone microtome is Class I under Rule 7(1). It becomes Class II only if it is meant to act as a calibrator, tester or quality-control support to another device, or to be connected to an active device already in Class II, III or IV.
Why is a cryostat treated the same way as a rotary microtome?
Because they are the same kind of non-invasive instrument with a different cutting action. The named entry groups the forms together, and the Canadian rule acts on the non-invasive character rather than on the cutting method.
What is the difference between a microtome and a cryostat?
A rotary or sliding microtome cuts sections of embedded tissue at room temperature. A cryostat is a microtome inside a cooled chamber, used to cut frozen sections quickly when a result is needed during surgery.
What should a laboratory keep with a microtome?
A maker, a model designation and a serial number, plus the licence number and the section-thickness range the instrument is checked against. Those are the fields that let an instrument be reconciled with a licence and recalled if a batch is affected.
Does a microtome need a quality-management certificate?
The certificate sits with the manufacturer rather than with the laboratory. Asking for the CAN/CSA-ISO 13485 certificate and the risk file is the way a buyer sees that the design and the records behind the instrument are in place.
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