Sterility test

A test for viable bacteria and fungi in a product that is claimed to be sterile, by membrane filtration or direct inoculation into culture media followed by incubation. In the Japanese Pharmacopoeia it is General Test 4.06 Sterility Test, a chapter harmonized with Ph. Eur. and USP. Because only a sample is tested, a passing result cannot prove that every unit is sterile; the assurance comes from process controls and media fills. Cell therapy products with short shelf lives may be released before the compendial result is available, or tested with validated rapid methods.