Which type of testing system contains living organisms for the purpose of testing autoclaves?

The correct answer is biological indicators, which are specifically designed to evaluate the effectiveness of sterilization processes such as autoclaving. Biological indicators contain viable microorganisms (often spores of highly resistant bacteria, such as Geobacillus stearothermophilus) that are exposed to the sterilization conditions. After the sterilization process, these indicators are incubated to determine whether the organisms have survived. If the spores remain viable after the autoclaving process, it indicates that the sterilization was unsuccessful.

The use of biological indicators is crucial because they provide a direct measure of the sterilization process's capacity to eliminate life forms that could potentially cause infection or contamination. In contrast, physical indicators rely on non-living measurements such as temperature or pressure, while chemical indicators use substances that change color or state in response to the conditions of sterilization but do not confirm the death of microorganisms. Quality control agents might help oversee the overall sterilization process but do not directly measure the biological efficacy of the sterilization itself. Therefore, biological indicators are the most reliable method for confirming that an autoclave has effectively sterilized its contents.