Bacteriostasis and Fungistasis
The Bacteriostasis and Fungistasis (B/F) test, also known as the Sterility and MPN Method Suitability test, is performed on a sterile product to determine if any inhibiting factors exist in the product which would invalidate a sterility test. This test is used with any product that needs any form of sterility testing in the course of validation or maintenance of a sterilization cycle.
The test complies with harmonized USP <71>, EP 2.6.1 and <JP XV, 54>; and AAMI/ISO 11737-2. Testing per 21 CFR 610.12 is also available upon request. Nelson Laboratories has extensive experience in overcoming inhibition due to antibiotics, chemicals or other substances in order to establish a valid method for the sterility test.
- USP 71
- EP 2.6.1
- JP14 54
- ANSI/AAMI/ISO 11737
- 21 CFR 610.12
Standard turn around times (TAT) are listed below. Ask an expert for a specific consultation on your product. If you are ready to submit your samples for testing, click here to fill out the Sample Submission Form.
|Code||Test||TAT (days)||Request Quote|
|BFS110||Sterility B/F Validation: USP method (filtration)||12||Add|
|BFS120||Sterility B/F Validation: USP method (standard)||12||Add|
|BFS130||Sterility B/F Validation: Isolator||12||Add|
|BFS140||Sterility B/F Validation: AAMI||9||Add|
|BFS150||Sterility B/F Validation: Non-Standard Organism Culture and Maintenance||21||Add|
|BFS160||Sterility B/F Validation for Re-Challenge Test: per organism||9||Add|
BFS110 - Sterility B/F Validation: USP method (filtration)
TAT: 12 days
BFS120 - Sterility B/F Validation: USP method (standard)
TAT: 12 days
BFS130 - Sterility B/F Validation: Isolator
TAT: 12 days
BFS140 - Sterility B/F Validation: AAMI
TAT: 9 days
BFS150 - Sterility B/F Validation: Non-Standard Organism Culture and Maintenance
TAT: 21 days
BFS160 - Sterility B/F Validation for Re-Challenge Test: per organism
TAT: 9 days
BFS110: 6 samples
BFS120: 6 samples
BFS130: 6 samples
BFS140: 6 samples
BFS160: Dependent on organism panel
Study OutlineBacteriostasis & Fungistasis (B/F, Sterility and MPN Method Suitability) testing should be performed prior to the sterility test procedure for a sample. In some cases it may be done at the conclusion of the sterility test, but if the sample is found to be bacteriostatic or fungistatic, the sterility test must be declared invalid.
For samples sterility-tested by the membrane filtration method: test samples are filtered through a 0.45 µm membrane filter and rinsed with a sterile diluent; the rinse is inoculated with the microorganisms and then the membrane filters are aseptically added to the appropriate media.
For samples sterility-tested by the direct transfer method: test samples are aseptically transferred into a volume of media sufficient to cover the sample; the containers of media containing the test samples are inoculated with the microorganisms.
For sample sterility-tested by the fluid pathway method: the fluid pathway of the test sample can be flushed with a sterile diluent and filtered; the rinse is inoculated with the microorganism and then the membrane filters are aseptically added to the appropriate media. The appropriate volume of the diluent used is determined by the maximum volume of the fluid pathway. Alternatively, the device can be filled with the appropriate media and inoculated with the microorganisms.
Although B/F (Sterility and MPN Method Suitability) testing is only required once for the life of a product, an annual revalidation is recommended. USP <71> requires a revalidation for any change.