Agar Plates in Canada vs the US: Which Culture Media Standard Applies?

September 27, 2026

Benchtop laboratory incubator with digital temperature display used to hold inoculated culture plates at temperature

Quick facts

An agar plate is two products sold as one: the dish and the medium poured into it. They are governed by different documents, so specifying only one specifies half the plate.
ISO 13132:2011 specifies requirements and tests for glass Petri dishes intended for general laboratory purposes and microbiological work. A polystyrene dish is outside that scope by material.
ISO 11133:2014 governs the medium rather than the dish, setting requirements for the preparation of culture media for microbiological analysis.
United States: the culture medium has named entries. A differential culture medium, a transport culture medium and a supplement for culture media are each Class I (general controls), and so is a microbiological incubator.
Canada: the Medical Devices Regulations classify by rule and by intended use, so a dish supplied as general laboratory material travels a different route from a medium sold with a diagnostic intended use.
The plate is the last step of a chain that starts with transport law: Canada requires packaging that meets the federal dangerous goods rules, and the United States uses triple packaging under 49 CFR 173.199.

A plate that fails rarely fails for a dramatic reason. It fails because the medium was prepared outside the requirements that apply to it, because the dish was outside its storage window, or because the specimen arrived in packaging that would not survive the journey. All three are documented failures, visible on the packing slip before the bench.

This article covers the two products inside an agar plate, the standards that reach each one, and the different regulatory shape of the same workflow in Canada and the United States.

What is an agar plate, and why are the dish and the medium separate purchases?

An agar plate is a shallow dish filled with a solid culture medium. The medium is usually built on agar, a polysaccharide that sets into a gel, with nutrients and often selective or differential agents added. The dish holds it, protects it and provides the surface the loop or swab works on.

That split matters commercially because the two halves carry different specifications:

The dish. Material, diameter, depth, venting or the absence of it, sterility, and the packaging that keeps it sterile until use. A standard 100 by 15 millimetre dish is the common format.
The medium. Its formulation, its performance against the organisms it is meant to grow or differentiate, its storage conditions, and its shelf life once poured.

A laboratory that pours its own plates owns the whole medium specification. A laboratory that buys prepared plates has outsourced that work, and accepts the supplier's performance claims in exchange. Both are legitimate; the difference is where the quality record lives.

Which standard covers the dish, and which covers the medium?

The two are separate documents, and the split is a useful thing to have in writing when a supplier describes a plate as "standard".

ISO 13132:2011 specifies requirements and tests for glass Petri dishes intended for general laboratory purposes and microbiological work. The material limitation is the point: a single-use polystyrene dish is a different product family, and a supplier who cites ISO 13132 for a plastic dish is citing a standard whose scope does not reach the product.

ISO 11133:2014 does the opposite job. It defines terms related to quality assurance of culture media and specifies requirements for the preparation of culture media intended for microbiological analysis of food, animal feed and samples from the food or feed production environment, as well as all kinds of water intended for consumption or used in food production. Those requirements are applicable to all categories of culture media prepared for use in laboratories performing microbiological analyses.

The quality system around the laboratory is set by ISO 15189:2022, which specifies requirements for quality and competence in medical laboratories, applies to laboratories developing management systems and assessing competence, applies to bodies confirming or recognising that competence, and applies to point-of-care testing.

Plate format	What it is	Standard of record	What to specify on the order
Glass Petri dish	Reusable glass dish, general laboratory and microbiological work	ISO 13132:2011	Diameter, depth, and the dish's verification and cleaning cycle
Single-use polystyrene dish	Sterile, ready to pour or ready to use	Not within the ISO 13132 material scope	Diameter, depth, sterility assurance, gamma or other sterilisation method
Prepared plate	Dish plus medium, poured and ready	Medium governed by ISO 11133:2014	Formulation, performance organisms, storage range, expiry

Are agar plates regulated the same way in Canada and the United States?

No, and the difference is easiest to see by looking at what each system actually files.

The United States regulates the medium and the equipment through named entries. A differential culture medium is a device that consists primarily of liquid biological materials intended to cultivate and identify different types of pathogenic microorganisms, classified Class I (general controls) and exempt from premarket notification subject to the limits in § 866.9. A transport culture medium is a semisolid, usually non-nutrient medium that maintains the viability of suspected pathogens in patient specimens while in transit from the collection area to the laboratory, also Class I. A supplement for culture media is Class I, and so is a microbiological incubator, which is a device with chambers or water-filled compartments in which controlled environmental conditions, particularly temperature, are maintained.

The same subpart extends across the bench: an anaerobic chamber, a microorganism differentiation and identification device and an automated zone reader that measures zone diameters of growth inhibition are each Class I (general controls).

Canada takes the rule-based route. Under the Medical Devices Regulations, SOR/98-282, an in vitro diagnostic device is defined by its intended use on specimens taken from the body, and classification follows the rules in Schedule 1. A dish or a bottle of agar supplied as general laboratory materials without a diagnostic intended use sits outside that regime; a medium sold with an in-vitro diagnostic intended use is assessed as an IVD and follows the licensing path its class requires.

Item	Canada	United States
Medium and its supplements	Assessed by rule and intended use; IVD claim drives licensing	Named entries such as 866.2320 and 866.2450, Class I
Transport medium	Assessed by intended use	866.2390 transport culture medium, Class I
Dish itself	General laboratory materials unless a diagnostic use is claimed	No dish-specific entry; the medium entries apply instead
Incubator	Assessed by rule and intended use	866.2540 microbiological incubator, Class I
Reading aids	Assessed by intended use	866.2170 colony counter and 866.2850 zone reader, both Class I
Licensing trigger	Device licence where the class requires it	Premarket notification, exempt for the Class I entries above

The practical consequence for a buyer is that a Canadian purchase order can be clean while the same items in the United States come with a chain of device classifications attached. Neither approach is stricter in the abstract; they attach the paperwork in different places.

Which laboratory rules apply once the plate is in use?

The plate is where two regulatory frameworks meet: the device rules that got it onto the bench, and the laboratory rules that govern what happens to the result.

In the United States the laboratory framework is built on the categories of tests by complexity, which sorts tests into waived tests, tests of moderate complexity including the PPM subcategory, and tests of high complexity, and on the criteria in 42 CFR 493.15 that describe the simple examinations and procedures eligible for a certificate of waiver. Where a laboratory introduces an unmodified, cleared test system, 42 CFR 493.1253 sets out the verification duties for accuracy, precision and reportable range before patient results are reported.

Canada relies on the quality standard and on provincial licensing. ISO 15189:2022 covers the management system and competence requirements, and the Clinical and Laboratory Standards Institute publishes the method documents a laboratory's quality manual will reference in either country, including its microbiology standards programme and its quality management systems programme.

Item	Canada	United States
Laboratory quality framework	ISO 15189:2022 plus provincial licensing	42 CFR part 493
Test tiering	Site licensing and accreditation scope	Waived, moderate and high complexity
Verification duty	Set by the quality standard and accreditation body	42 CFR 493.1253 for unmodified cleared systems
Method documents	CLSI documents referenced in the quality manual	CLSI documents referenced in the quality manual
Media preparation requirements	ISO 11133:2014	ISO 11133:2014

Containment expectations are set out in the World Health Organization's laboratory biosafety manual, and the reason plate counts matter is covered in its antimicrobial resistance fact sheet.

How does the specimen reach the plate, and what governs that?

A plate is the end of a journey that starts outside the laboratory, and the transport rules differ enough between the two countries that they change the packaging a laboratory buys.

Public Health Ontario's specimen acceptance criteria require that specimen packaging meet the minimum federal Transportation of Dangerous Goods packaging requirements and that the specimen not be leaking. The same page sets out the identity requirements, and states that where a critical specimen has identifiers that are missing, incomplete or conflicting between specimen and requisition, a signed waiver from the submitting health care provider is required before the specimen is processed and reported. The test information index carries per-test collection and handling requirements, and the kit and test ordering instructions cover ordering.

The United States treats the same shipment as a hazardous material. Under 49 CFR 173.199 a Category B infectious substance must be in triple packaging made up of a primary receptacle, a secondary packaging and a rigid outer packaging, with the outer packaging carrying the UN3373 square-on-point mark and the proper shipping name.

Item	Canada	United States
Transport law	Transportation of Dangerous Goods Regulations	49 CFR hazardous materials regulations
Packaging requirement	Meet the minimum federal TDG packaging requirements	Triple packaging: primary, secondary, rigid outer
Leak criterion	The specimen must not be leaking	Performance-based, verified by drop test
Identifier failure	Signed waiver required, otherwise the test is cancelled	Laboratory rejection criteria
Reference page	Public Health Ontario specimen acceptance criteria	49 CFR 173.199

Which consumables does a culture bench consume with the plates?

The plate is one line, and the recurring spend sits around it.

Dishes and prepared media. Sterile polystyrene petri dishes are bought by diameter and case count; the medium poured into them carries the ISO 11133 requirements.
Sampling and transfer. Many specimens arrive on a swab. Foam-tipped swabsticks and double-tipped cotton swabs cover collection and bench transfer.
Primary containers. A graduated specimen cup is the primary receptacle for the samples that do not arrive on a swab.
Transport packaging. 95 kPa specimen transport bags must be part of a system documented against the applicable packaging standard, with a separate compartment for the requisition.
Incubation capacity. Whatever is inoculated has to be held at temperature, and a benchtop incubator is the same equipment family as the incubator entry discussed above.

Specimen transport bag with biohazard printing held in hand at a laboratory bench

For a laboratory or clinic buying these lines together, the ordering route is worth setting up once.

Sources

Ordering for a clinic, lab or care home? Wholesale and multi-site ordering covers account setup and case pricing, and the B2B wholesale collection lists the lines stocked for institutional buyers. Laboratories that also run an in-house sterilizer can start with the biological indicator 5-pack trial.

Related reading

Frequently Asked Questions

Are agar plates regulated the same way in Canada and the United States?

No. The United States gives the medium and the equipment named entries: a differential culture medium is 21 CFR 866.2320, a transport culture medium is 866.2390 and a microbiological incubator is 866.2540, all Class I (general controls). Canada classifies by the rules in Schedule 1 of the Medical Devices Regulations applied to device definitions and intended use, so a medium sold with an in-vitro diagnostic use is assessed as an IVD and a dish supplied as laboratory material is not.

Which standard covers the dish, and does it cover a plastic dish?

ISO 13132:2011 specifies requirements and tests for glass Petri dishes intended for general laboratory purposes and microbiological work. Because the scope is stated in terms of glass, a single-use polystyrene dish sits outside it, so the buyer should specify diameter, depth, sterility assurance and sterilisation method directly.

Which standard covers the culture medium?

ISO 11133:2014 defines terms related to quality assurance of culture media and specifies requirements for the preparation of culture media intended for microbiological analysis of food, animal feed, food-production samples and water used in food production, and its requirements apply to all categories of culture media prepared for use in laboratories performing microbiological analyses.

Does the incubator used with plates have its own device entry?

In the United States it does. 21 CFR 866.2540 identifies a microbiological incubator as a device with chambers or water-filled compartments in which controlled environmental conditions, particularly temperature, are maintained, intended to cultivate microorganisms and aid in the diagnosis of disease, and classifies it Class I (general controls).

What makes a specimen unacceptable before it ever reaches the plate?

In Canada the common triggers are packaging that does not meet the minimum federal Transportation of Dangerous Goods packaging requirements, a leaking specimen, and identifiers that are missing, incomplete or conflicting between specimen and requisition, which require a signed waiver before the specimen is processed and reported. In the United States a Category B shipment must be in triple packaging under 49 CFR 173.199.

What should a purchase order for plates specify?

For the dish: diameter, depth, material, sterility assurance and the sterilisation method. For the medium: formulation, performance organisms, storage range and expiry. For prepared plates: the poured-on date basis and the storage conditions the supplier states. Separating those three groups is what keeps the order clean.

CliniEco Medical supplies laboratory consumables, culture bench lines and the wider clinical catalogue described in this article. Health Canada MDEL #35334. This article is written for laboratory, clinic and procurement professionals and is not clinical guidance; method selection and result interpretation belong to the laboratory director.