Sterilization Techniques PDF

Sterilization Sec 4  Sterilization Physical Chemical Mechanical  Physical agents heat Radiation Dry heat UV Wet heat(moist)  Dry heat Oven ×Ex...

Sterilization Sec 4  Sterilization Physical Chemical Mechanical  Physical agents heat Radiation Dry heat UV Wet heat(moist)  Dry heat Oven ×Explant Oven ×media Flame Metal tools Electric sterilizer  Wet heat (moist) Autoclave execution for contaminated media and contaminated cultures. sterilization for media, glass ware ,plastic ware like filter and tips , coat , cotton plug and Distilled water. Autoclave is basically a large-sized but sophisticated pressure cooker. Sterilization by steam under prussure ( wet heat method ) Temp 121°C Pressure 1to1.5 bar (1.2 bar) Time depends on the volume of media (direct relationship) Autoclave ×Explant ×metal tools Physical agents Radiation  Radiation UV has limited penetration in air, so sterilization only occurs in a small area around the lamp. However, it is relatively safe and is quite useful for sterilizing small areas, like laminar flow hoods. UV ×Explant × Sodium hypochlorite × closed door  UV + Sodium hypochlorite (√) UV + Ehanol 70% Chlorine gas is released which is harmful gas UV + closed door of laminar (O₃) ozone gas accumulation which cause Explosion  Tap water Chemical agents: to sterilize Explant Chemicals 1. Ethanol 70% Sterilized Distilled Water 2. H2O2 3. Sodium hypochlorite) 4. Silver nitrate (AgNO3) 5. Bromine water Tween 20 6. HgCl2 ( To remove surface tension To increase efficiency of sterilization )  Ethanol 70% Dehydration Coagulation H2O2 Safe grain has to sterilize for long time seed has to sterilize for short time Silver nitrate (AgNO3) Toxic on embryo √ grain Bromine water × Seed HgCl2 √ just for underground stem and root / Hard removing (residual) so should wash 3 times by S.D.W  Mechanical Filtration For heat sensitive material: 1. Ascorbic acid AA 2. Some growth regulators like IAA)