AUTOCLAVE - Dr. Sudheer Kher Specimen SAQ

Principle- Physical method of sterilization by using Steam under pressure.
Advantages of steam – High penetration, Latent heat.
Temp & Time – 121 C X 20 min achieved by 15 lb/sq inch
Mode of destruction – Coagulative denaturation.
Types of autoclaves – Jacketed and non-jacketed.
Problems of non jacketed –
1. Air discharge not satisfactory
2. Load remains moist at the end.
Jacketed autoclave – Both the above problems are taken care of by
a) Having air discharge at the bottom
b) Separate circulation of steam within the jacket after holding period allows drying of the load.

Articles sterilised – Most culture media (barring those containing blood/ serum/ eggs/sugars), dressings & bandages, bowls, instruments, syringes, glassware, glass and metal syringes, filters, rubber goods etc.

Articles not sterilised – Talc, Oils, Greases and Fats. Blood/serum/egg/sugar containing media.

Autoclave efficiency tests –
a) Physical – Thermocouple, Recording drums, thermometers
b) Chemical – Bowie-Dick tapes, Browne’s tubes
c) Biological – Using B. stearothermophilus spores