Microbio Laboratory

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Sterility Testing (IP/USP)

All test containers are incubated at specific temperatures for at least 14 days, regardless of whether filtration or direct inoculation test method is used.

Sterility Testing Methods

Direct Inoculation (Immersion)

In the Direct Inoculation method the samples are inoculated directly into tubes or bottles that contain an appropriate medium and are incubated for a period of 14 days.

Membrane Filtration and Direct Transfer

The membrane filtration method requires the sample to first pass through a membrane capable of retaining microorganisms. An appropriate amount of rinse fluid is then passed through the filter before transferring the membrane into the two test medium.

In both test methods the test article or membrane is incubated for 14 days in the test media. The majority of biological samples will be tested using the immersion method. However, for test articles with large volumes in which the entire contents must be tested or if there is a substance within the test article that is known or determined to be bacteriostatic or fungistatic , the membrane filtration method may be required.