Bacteriostasis & Fungostasis (B&F) Testing
Ensure the validity of your sterility results. Our B&F studies confirm that your medical device does not interfere with microbial growth, preventing false-negative results during final product release.
Bacteriostasis and Fungostasis (B&F) testing is a critical regulatory requirement that must be performed prior to or in conjunction with a sterility test. The purpose of this study is to demonstrate that the medical device itself—or its physical/chemical properties—does not inhibit the growth of microorganisms in the culture media. Without this validation, a „sterile” result may actually be a „false negative” caused by the device’s antimicrobial properties suppressing microbial growth during the test.
Why B&F Testing is Mandatory
A B&F assay is essential to prove that the sterility test methodology is suitable for your specific test article. It is required in the following scenarios:
- New Product Development: To establish the initial sterility testing protocol.
- Manufacturing Changes: Whenever raw materials or production processes are modified, as these can change the antimicrobial profile of the device.
- Methodology Alignment: The B&F test must strictly reflect the actual sterility test methodology (e.g., immersion or membrane filtration) used for the final product.
Our Methodology: USP Compliance
At EBI, we perform B&F testing according to USP <71> standards to ensure global regulatory acceptance.
- Media Preparation: The sterile medical device is placed into Trypticase Soy Broth (TSB) and Fluid Thioglycollate Media (FTM).
- Inoculation: A low number of viable challenge microorganisms (bacteria and fungi) are added directly to the media containing the device.
- Growth Comparison: We monitor the containers for visible growth. If the organisms grow as expected, it proves the device does not have bacteriostatic or fungistatic properties that would mask contamination.
- Neutralization: If bacteriostatic or fungistatic properties are detected, further testing is suspended. Any specialized material preparation must strictly follow the manufacturer’s instructions. We do not modify rinse volumes or use neutralizing agents outside of the validated instructions for use, as the material must
Sample Requirements & Timeline
To provide a robust validation, we require a specific number of sterile samples to mirror the final sterility test conditions.
- Turnaround Time: Standard completion in 4 weeks.
- Minimum Quantity: At least 6 sterile samples are required.
- Compliance: Testing is performed in accordance with USP <71>.
Standards & Regulatory Background
- USP <71>: Sterility Tests.
- ISO 11737-2: Sterilization of health care products — Microbiological methods — Part 2: Tests of sterility performed in the definition, validation and maintenance of a sterilization process.
How We Work
Discovery & Insight
We begin with an in-depth consultation to understand your needs, challenges, and objectives. This helps us define the right strategy and scientific approach for your project.
Design & Development
Our experts translate your vision into actionable plans — combining innovative research, data, and technology to build precise and reliable solutions.
Delivery & Support
We implement the solution with full transparency and ongoing communication. After delivery, we stay involved — supporting you with optimization, updates, and future improvements.
FAQ: Frequently Asked Questions about B&F
Can I skip B&F testing if I know my materials are non-toxic?
No. Regulatory bodies require documented evidence that the test media can support growth in the presence of the device. Even „inert” materials can sometimes leach substances or alter the pH of the media, interfering with the test.
Is this test required for every batch?
B&F is a validation study, not a routine release test. It is typically performed once per product type unless there is a change in the product or the sterility test method.
Can I skip B&F testing if I know my materials are non-toxic?
No. Regulatory bodies require documented evidence that the test media can support growth in the presence of the device. Even „inert” materials can sometimes leach substances or alter the pH of the media, interfering with the test.
Is this test required for every batch?
B&F is a validation study, not a routine release test. It is typically performed once per product type unless there is a change in the product or the sterility test method.
Contact with us
We’re open to collaboration and research partnerships. Fill out the form — our team will respond as soon as possible.
Location:
Europejski Instytut Biomedyczny sp. z o.o.
ul. Bartycka 63A lok. 6, 00-716 Warszawa
Mail:
contact@ebi.bio
Phone:
+48 22 780 06 32
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