Assistant Laboratory Animal Technician (ALAT) Practice Exam

What is the most sensitive method to verify autoclave effectiveness?

1. Pressure test

2. Chemical indicator

3. Physical measurement

4. Biological indicator

The correct answer is: Biological indicator

The most sensitive method to verify autoclave effectiveness is through the use of a biological indicator. Biological indicators contain viable microorganisms that are resistant to the sterilization process. When these indicators are autoclaved, their survival or death is assessed to confirm whether the sterilization conditions were adequate to eliminate all potential pathogens. Using biological indicators provides a direct measure of the sterilization process's effectiveness, as it tests the actual ability of the autoclave to destroy a defined number of resistant organisms under the specific conditions used in the autoclaving process. If the organisms are killed, it indicates the sterilizing conditions were met; if they survive, it suggests that the process may not have been effective. This makes biological indicators the gold standard in monitoring sterilization efficacy, as they are more definitive than other verification methods. In contrast, pressure tests, chemical indicators, and physical measurements offer less sensitivity. Pressure tests check the pressure levels but do not guarantee that the sterilization process effectively killed all microorganisms. Chemical indicators respond to specific environmental conditions but do not confirm the lethality of the process. Physical measurements, such as temperature and time, provide information on the parameters used but do not directly verify the effectiveness against resistant organisms. Thus, the use of biological indicators stands out