Method suitability

An experiment showing that a microbiological method recovers organisms in the presence of the product. Low numbers of test organisms, not more than 100 CFU, are added to the product prepared as in routine testing, and recovery is compared with a control without product. For counts, recovery must be within 50–200%; for sterility tests, growth must be visibly comparable. If not, dilution, neutralisers or filtration are used until the method passes.