OSMT (Ontario Society of Medical Technologists) Practice Exam

Biological indicators are used in the autoclave process primarily to confirm that sterility has been achieved. These indicators typically contain viable spores of a highly resistant microorganism, such as Geobacillus stearothermophilus, which are placed inside the autoclave load. After the sterilization cycle is complete, the indicators are taken out and cultured to determine if any growth has occurred. If the spores have been successfully killed, this indicates that the sterilization conditions—such as temperature, time, and steam penetration—were sufficient to achieve sterility.

While other indicators might assess specific conditions like temperature or pressure, biological indicators focus specifically on the final outcome of the sterilization process—whether or not all microorganisms, including resistant spores, have been eradicated. This crucially assures that the items sterilized are safe for use in medical and laboratory settings.