Western Maricopa Education Center (West-MEC) Medical Assisting ADE Practice Exam

The idea here is verifying that a sterilization cycle actually achieves the required level of microbial kill by using biological indicators. Spore testing uses non-pathogenic spores placed on paper strips to challenge the sterilizer; if the spores are killed, it indicates the cycle reached the necessary lethality for that load. After exposure, the strips are incubated to see if the spores germinate—growth means the process didn’t achieve sterilization for that run, while no growth confirms effective sterilization. Different spores are chosen based on the sterilization method (for steam, Bacillus stearothermophilus is common; for ethylene oxide, Bacillus atrophaeus). This approach goes beyond what chemical indicators or visual checks can do, because it directly tests whether the sterilization process can destroy hardy spores, not just whether the equipment reached a certain temperature or the packaging looks correct.