Which of the following methods is most commonly used to achieve sterilization in microbiology laboratories?

• A. Pasteurization at 72°C for 15 seconds
• B. Autoclaving at 121°C for 15 minutes
• C. Filtration using 0.45 μm filters
• D. Refrigeration at 4°C

Answer: (B)

Verified step by step guidance

1. Understand the concept of sterilization: Sterilization is the process of completely eliminating or killing all forms of microbial life, including spores, from a surface, fluid, or medium.
2. Review the methods listed and their typical uses: Pasteurization (72°C for 15 seconds) is a heat treatment that reduces microbial load but does not achieve sterilization; it is mainly used for food safety.
3. Consider filtration using 0.45 μm filters: This method physically removes many bacteria but cannot remove viruses or smaller microorganisms and does not kill microbes, so it is not a sterilization method.
4. Evaluate refrigeration at 4°C: This method slows microbial growth but does not kill microbes, so it is not a sterilization technique.
5. Recognize autoclaving at 121°C for 15 minutes: This method uses pressurized steam to kill all microorganisms, including spores, and is the standard and most commonly used method for sterilization in microbiology laboratories.