What does a sterility test show?
Sterility testing checks a sample from a batch for living microorganisms. Under USP <71>, a common reference for sterility testing, samples are incubated for at least 14 days and then examined for growth.
What a "sterile" result means
No contaminating microorganisms were found in the sample under the test conditions. It does not confirm that the whole batch is free of contamination. Sterility is mainly assured by validating the sterilization or aseptic process itself. The USP chapter states that its procedures are "not by themselves designed to ensure that a product or batch is sterile."
What to ask when you see a result
- Which batch does the result cover?
- Which lab ran the test, and is it accredited?
- How is the process that makes the product sterile validated?
Source: Advanced Release Laboratories, "USP <71> Sterility Testing" (summary of the USP chapter). arlok.com
Educational content. Not medical advice.