Biological indicator (BI) is type of monitoring which provides direct evidence that sterilization process conditions are sufficient to kill spores. It uses microbes that are highly resistant to the type of sterilization process you are monitoring.
BIs are considered the gold standard of load sterilization monitoring. They are widely recommended as the preferred device for monitoring and releasing loads.
Biological indicators (BI) are routinely used within the pharmaceutical, food, and medical devices industries to monitor the efficacy of various sterilization processes. These processes include dry heat, ethylene oxide, hydrogen peroxide, moist heat (steam sterilization), chlorine dioxide, and peracetic acid. Biological indicators (or bio-indicators) are preparations of a specific microorganism with high resistance towards particular sterilization methods.