USP<55> Biological Indicators

Biological Indicators are used in the validation, performance verification, and/or with-use verification of cleaning and sterilization processes, such as steam sterilization, ethylene oxide sterilization, and gamma irradiation.

They typically contain a very high concentration of bacterial endospores which are the most resistant sterilization, and are available in many formats corresponding to their use.

In order to meet the requirements of USP, the population of biological indicators must be verified. This involves processing and/or suspending the indicator in a diluent, diluting it to the countable range, and enumerating.

Probiotic label claim verification

Probiotic products are typically labeled with a population concentration. As with nutritional supplements, vitamins, and drugs, it is important to ensure any product contains the  specified or labeled range of therapeutic substance.

Organism verification:

The organism or organisms present on the label claim for a probiotic or biological indicator should be identified to ensure purity. Microbial Limits Testing should also be employed to ensure purity and safety.