How to autoclave?

Brief explanation of sterilisation process

Sterilisation using superheated, saturated steam in an autoclave.

In the medical sector and in microbiological research as well as in materials testing, reusable, temperature-stable equipment and materials are autoclaved.

What are the advantages of this type of sterilisation?

Autoclaving is one of the most important methods of germ destruction. Sterilisation using saturated, superheated steam is currently the safest sterilisation method. The condensation of steam on the object to be sterilized releases energy which causes irreversible damage to the microorganisms.

An autoclave cycle is divided into four sections:

  • Rise time

  • Compensation time

  • Sterilisation phase

  • Cool-down phase

The first stage is the rise time. The interior of the autoclave is vented during this time. In doing so, the atmospheric air is displaced from the interior and replaced by saturated, superheated steam. Venting takes place using a flow process or through fractioned venting; once venting is complete, the vent valve is closed. This marks the start of the compensation time. After this period, every point of the item to be sterilised reaches the required temperature due to the effect of the saturated steam. After this, the actual sterilisation phase begins. The duration of sterilisation is dependent on both germ loading and sterilisation temperature. Autoclaving at 121°C for 15 min is seen as standard. Prions require at least 30 min at 132-134°C and 3 bar pressure in order to be inactivated or destroyed. The cool-down phase, and thus the end of the autoclave cycle, starts after the sterilisation time.

Language Selection