What are vials or strips that contain harmless bacterial spores and are used to determine whether sterilization has occurred called?

• A. Biologic Indicators
• B. Chemical Indicators
• C. Physical Indicators
• D. Temperature Probes

Answer: (A)

Biologic indicators are vials or strips that contain harmless bacterial spores and are used to verify sterilization by showing whether the process truly kills microbes. After a sterilization cycle, these indicators are incubated to see if the spores survive and grow. If there’s no growth, it confirms that the sterilization was effective at inactivating even hardy organisms. This direct test of microbial kill is why biological indicators are considered the most definitive way to confirm sterilization.

Chemical indicators, on the other hand, only reveal that the sterilant reached and interacted with the item (such as a color change), not whether any microbes were killed. Physical indicators monitor parameters like time, temperature, and pressure but do not prove that all organisms were destroyed. Temperature probes measure heat but don’t indicate sterility.