AST Surgical Technologist Practice Exam

Which of the following monitors provides positive assurance of sterility?

1. Physical

2. Biological

3. Chemical

4. Visual

The correct answer is: Biological

The biological monitor offers the most definitive confirmation of sterility, as it utilizes live microorganisms to test the efficacy of the sterilization process. When using a biological monitor, specific bacterial spores known for their resistance to the sterilization process are introduced into the sterilizer load. After the sterilization cycle, the monitor is incubated to check for any growth of the spores. If no growth occurs, it confirms that the sterilization process was effective, providing positive assurance that the items processed are sterile. This method goes beyond other forms of monitoring, such as physical monitors, which track parameters like temperature and pressure, or chemical indicators, which only show that certain conditions were met but do not confirm that sterility was achieved. Visual checks, though necessary for identifying obvious issues, do not provide a guarantee of sterility either. Hence, the biological monitor is the gold standard for confirming that sterilization has been successful and that the items are safe for use.