Which of the following best describes the most efficient sterilizing conditions in a steam autoclave?

• A. 140 B0C at 2 atm for 5 minutes
• B. 121 B0C at 15 psi for 15 minutes
• C. 100 B0C at 1 atm for 30 minutes
• D. 160 B0C at atmospheric pressure for 1 hour

Answer: (B)

Verified step by step guidance

1. Understand that sterilization in a steam autoclave relies on moist heat under pressure to kill all microorganisms, including spores, by denaturing proteins and disrupting cell membranes.
2. Recognize that the standard and most efficient sterilizing condition commonly used is 121\degree C at 15 psi (pounds per square inch) above atmospheric pressure for 15 minutes, which ensures effective sterilization without damaging materials.
3. Note that increasing temperature or pressure beyond this standard can reduce sterilization time but may damage heat-sensitive materials, while lower temperatures or pressures require longer exposure times and may not achieve sterilization.
4. Compare the given options by considering both temperature and pressure: 121\degree C at 15 psi for 15 minutes is the established optimal balance for effective sterilization in most microbiology settings.
5. Conclude that the option stating 121\degree C at 15 psi for 15 minutes best describes the most efficient sterilizing conditions in a steam autoclave.