Autoclave Autoclave



Autoclave,invented in 1879 by Charles Chamberland, is a pressure vessel thatsterilises supplies and equipments by subjecting them to hightemperature and pressure for some time depending on the contents andthe size of the load. Autoclave, in other words, is a steam-pressuresteriliser (Norgard, 2010). Autoclaves are useful in medicine, bodypiercing, mycology, microbiology, podiatry, veterinary science,tattooing, among others. The autoclave vessels vary in size dependingon their functions and the media to be sterilised.

Pressurein the autoclave vessel influences the temperature hence, the timingof the sterilization process. According to basic principles ofchemistry, when gas pressure increases, its temperature alsoincreases proportionally. When water is boiled up to 100°C,it produces steam. If the steam is trapped and then compressed, itspressure increase hence, the temperature rises up. Normally,autoclaves have sterilizing chamber to place the components to besterilised and a steam jacket to maintain steam (Norgard, 2010). Thehot steam flows into the sterilizing chamber through the steam jacketforcing the cool air out. At the same time, another valve increasesthe pressure of the steam above the normal atmospheric pressure, aswell as its temperature. As a result, the superheated water moleculesswiftly convert heat into microorganisms. Correspondingly, thedestruction of resistant bacteria reduces to about fifteen minutes.

Comparisonof Microbial Destruction Ability


Dry Heat

Moist Heat

Principle of destruction

Kills organism through protein oxidation process

Kills organism through protein coagulation process

Procedure for destruction

Kills microorganism by oxidation of essential cell constituents using high temperature of 160°C for one hour

Kills microorganisms by denaturing proteins and enzymes using a temperature of 121°C for fifteen to thirty minutes

Thermal death time

High thermal death time correspond to high temperature and vice versa

High thermal death time correspond to low temperature and vice versa.

Apparatus required

Glassware, metal instruments, syringes, paper, or any apparatus that is not destroyed by high temperature

Dry heat oven, pipettes, tubes, gas cookers, among others


Less effective for killing microorganisms

More effective for killing microorganisms


Norgard,L. (2010).&nbspAutoclave&nbsp(1.oplag ed.). Århus: Galleri Profilen.

Petrofsky,J., Berk, L., Bains, G., Khowailed, I. A., Hui, T., Granado, M., …&amp Lee, H. (2013). Moist Heat or Dry Heat for Delayed Onset MuscleSoreness.Journalof clinical medicine research,&nbsp5(6),416.