Certified Surgical Technologist (CST) Practice Exam

Which of the following monitors provides positive assurance of sterility?

1. Chemical

2. Mechanical

3. Biological

4. Clerical

The correct answer is: Biological

The correct choice is biological monitoring, as it directly assesses the effectiveness of the sterilization process. Biological indicators contain viable microorganisms that are highly resistant to the sterilization technique used. After the sterilization process, these indicators are incubated to check for growth; if there is no growth, it confirms that the sterilization process was effective and that the items are sterile. This type of monitoring provides the most reliable assurance of sterility compared to other methods available. Chemical monitoring involves indicators that change color or display a specific characteristic when exposed to certain sterilization conditions, but these do not guarantee that the microorganisms have been eliminated. Mechanical monitoring refers to the observation of sterilizer parameters such as temperature and pressure during the cycle, which are important but do not confirm sterility on their own. Clerical monitoring pertains to checking and documenting the sterilization process but lacks any form of assurance about the sterility of the items processed. Thus, biological monitoring stands out as the method that provides definitive proof of sterility.