What is the correct temperature and time to sterilize media in an autoclave/steam oven?

What is the correct temperature and time to sterilize media in an autoclave/steam oven?

• A. 121 C for 15 mins @100kPa
• B. 100 C for 30 min at 50 kPa
• C. 135 C for 5 min at 150 kPa
• D. 110 C for 20 min at 80 kPa

Answer: (A)

In an autoclave, sterilization relies on saturated steam at a high temperature and enough exposure time to kill even tough organisms like spores. The standard cycle used for many culture media is 121°C held for about 15 minutes under sufficient pressure to maintain that temperature. This combination is widely validated to achieve sterility for most media without damaging the contents when loaded properly. The setting with 121°C for 15 minutes at roughly 100 kPa matches this common sterilization practice, which is why it’s the best choice. The other options don’t meet the same proven combination: they either don’t reach the necessary temperature, or they fail to provide a proven 15-minute exposure at that temperature, making them less reliable for guaranteeing sterility.

In an autoclave, sterilization relies on saturated steam at a high temperature and enough exposure time to kill even tough organisms like spores. The standard cycle used for many culture media is 121°C held for about 15 minutes under sufficient pressure to maintain that temperature. This combination is widely validated to achieve sterility for most media without damaging the contents when loaded properly.

The setting with 121°C for 15 minutes at roughly 100 kPa matches this common sterilization practice, which is why it’s the best choice. The other options don’t meet the same proven combination: they either don’t reach the necessary temperature, or they fail to provide a proven 15-minute exposure at that temperature, making them less reliable for guaranteeing sterility.