Frequently Asked Questions – Certified Reference Materials

Below are the most common questions we have received regarding our ISO 17034 Certified Reference Materials for Antimicrobial Testing. If your question is not here, please reach out to us at

General information on our Certified Reference Materials can be found here.

Information on customs orders can be found here. 

1. What is a Certified Reference Material (CRM)?

Situ Biosciences’ CRMs are innovative Test Standards developed from decades of antimicrobial testing expertise in the global market. They are intended to be utilized as Test Controls in specified Antimicrobial Methods; being characterized for their performance.


ISO 17034:2016, the standard which establishes the requirements for Reference Material Producers, defines CRMs as a “reference material characterized by a metrologically valid procedure for one or more specified properties, accompanied by a reference material certificate that provides the value of the specified property, its associated uncertainty, and a statement of metrological traceability”.

2. What is the benefit of using a CRM in my Antimicrobial testing?

Achieving the Certified Values for both Test Controls validates the method performance, and additionally establishes a baseline for comparison to a product’s performance. On top of guaranteeing the highest quality of testing available when utilized in your testing with Situ, there are advantages to utilizing our CRMs within your internal processes.


CRMs can be used to meet ISO 17025 requirements for Method Verification and Validation,  Employee Training, Proficiency Testing and more for testing laboratories. When utilized during the R&D and Manufacturing phases, CRMs increase insight into the product performance and increase confidence in internal results, which naturally decreases the external testing necessary.

3. What is a Certified Value and how is it determined?

Certified Values are the properties a given Certified Reference Material is guaranteed to achieve by the producer. Generally, this could include color, weight, test performance, purity, or many other properties of a product. Not all properties of a Product are required to be Certified Values, only the properties related to the claims of the Product.


Certified Values for Situ Biosciences Products are for the results that will be achieved through performance of a Standard Method. These values have been determined through the relevant Standard Method performance in Situ Biosciences’ facilities, which are accredited to the following:

  • ISO/IEC 17025 – General Requirements for the Competence of Testing and Calibration Laboratories
  • ISO 17034 – General Requirements for the Competence of Reference Material Producers
  • U.S. EPA FIFRA Good Laboratory Practice Standard per 40 CFR Part 160 and TSCA Part 792


All Certified Reference Materials are required to state the Certified Values that are associated with them. Otherwise, they can only be considered Reference Materials.

4. Does your Certified Antimicrobial Test Control come pre-inoculated?

No, our Certified Test Controls are a material intended to be inoculated by the customer at the time of method performance. The Test Controls have been tested with and certified for the organisms most commonly utilized in that method, based upon our testing experience and the associated Standard Documents.


Information related to organisms utilized for a specific product line are available upon request.

5. Am I required to use the CRM?

Certified Reference Materials are required to be used under certain conditions for ISO 17025 compliance.


ISO 17025:2017 section 6.5.3  states ”When metrological traceability to the SI units is not technically possible, the laboratory shall demonstrate metrological traceability to an appropriate reference, e.g.: a) certified values of certified reference materials provided by a competent producer;”

6. Will using a CRM improve my product’s performance?

CRMs will not directly impact how a product performs in a given method, but will provide insight into the performance of the product and a consistent long-term comparison. This insight will allow a customer to make strategic decisions when implementing any design changes to that product or any future products that are developed.


Our goal is that the inclusion of Certified Test Controls in Antimicrobial Methods will accelerate the continuously improving quality of Laboratory Testing, and therefore antimicrobial product development, throughout the industry.

7. How many samples do I receive in a single package?

Certified Reference Materials are provided in test sets consisting of Treated and Untreated Test Controls. One test set consists of the specified number of individual samples to perform the associated Antimicrobial Method once. Therefore, the exact number will vary from product to product.


For each product, the number that constitutes a test set is determined through the relevant Method’s requirements on the sample dimensions, weight, and/or number of replicates to be tested. Larger quantities can be ordered upon request.

8. What is the difference between a treated and untreated Antimicrobial Method Test Control?

Test Controls are a vital component to verifying the proper performance of a method. By establishing known values for samples, they establish a baseline comparison for evaluating a product’s performance over time.


Treated Test Controls are designed to achieve the ideal performance of a method, and Untreated Test Controls are designed to have an extremely poor performance. The desired outcome of a given Method determines how each control is expected to perform.


By including both test controls in the performance of a method, a higher level of confidence in whether or not a Method was performed properly will be achieved.