Question

Give two examples of sterilization techniques and describe them

Answer 1

Sterilization is the process of killing, deactivating or stopping the growth of any biological contaminant on surfaces or substances to make the conditions sterile and asceptic. Some methods of sterilisation are heating, autoclaving, irradiation, use of chemical agents and so on.

1)Irradiation- UV, Gama rays are commonly used electromagnetic radiation, where the radiation penetrates the membrane and causes DNA damage thus preventing the growth of the microorganisms. For eg. UV radiation causes the formation of thymine dimers in DNA which hampers replication.

2)Autoclaving- It uses steam at high pressure generated at 121 degree celcius and 15 lbs pressure to destroy microbes and spores.

3)Chemical agents- 70% ethanol causes pores by dehydration which leads to the release of microbial cell contents and thus its destruction. Some other chemicals such as sodium hypochlorite, destroy microbes by produucing free radicals that oxidise their cellular components.