Which of the following is true of autoclaving?

• A. It operates at a temperature of 60^ext{o}C.
• B. It is effective only against viruses, not bacteria.
• C. It is a dry heat sterilization method.
• D. It uses pressurized steam to sterilize materials.

Answer: (D)

Verified step by step guidance

1. Understand that autoclaving is a sterilization method commonly used in microbiology laboratories to eliminate all forms of microbial life, including spores.
2. Recall that autoclaving uses steam under pressure to achieve sterilization, which allows the temperature to rise above the normal boiling point of water (100\^\{\circ\}C).
3. Recognize that the typical operating temperature of an autoclave is around 121\^\{\circ\}C, not 60\^\{\circ\}C, which is too low for effective sterilization.
4. Note that autoclaving is a moist heat sterilization method, not a dry heat method, meaning it relies on steam rather than dry air.
5. Conclude that the correct statement is that autoclaving uses pressurized steam to sterilize materials, making it effective against bacteria, viruses, spores, and other microorganisms.