AUTOCLAVING

Autoclaving sterilizes glassware, media and lab waste using pressurized steam (121°C, about 15 psi). The combination of heat and pressure kills bacteria, fungi, viruses and even heat-resistant spores.

WHAT YOU NEED?

• Autoclave

• Autoclave-safe bins, bottles or bags

• Autoclave indicator tape

• Heat-resistant gloves

STEPS

1. Place items in autoclave-safe containers. Loosen the caps on bottles so steam can get in and pressure can escape.

2. Stick a strip of autoclave indicator tape on each load.

3. Load the autoclave without overcrowding it, so steam can circulate.

4. Choose the right cycle: a liquid cycle for media, or a gravity (dry) cycle for empty glassware and consumables.

5. Run the cycle at 121°C for at least 15–20 minutes (longer for large volumes).

6. Wait until the pressure has dropped and the chamber has cooled before opening the door.

7. Wearing heat-resistant gloves, remove the load and check that the indicator tape has changed colour.

8. Tighten caps once bottles have cooled, then store.

TIPS

• Never seal bottles tightly before autoclaving; they can crack or burst.

• Indicator tape shows the load got hot, not that it is fully sterile, so always use the correct cycle time.

• Open the door slowly and stand back from the steam.