5. DRY HEAT
• Flaming:- Slides coverslip & mouth of Test Tube can be sterilize by passing them through flame a few no.
of
time.
• Red Heat:- Effective Sterilization of articles can be heated to
redness om flame.
• Incineration:-
• Sterilization along with Significant reduction in volume
of infectious hospital waste.
for e.g:- -Human Pathological waste- organs, teeth gums
-Cytotoxic Drugs
-Animal carcasses
6. Hot Air Oven:- It is 1st introduced by Louis Pasteur.
Temperature -160˚C For 2 hrs
Material Sterilized- -Glassware like glass syringes , petri dishes, flasks,
pipettes and test tubes.
-Surgical Instruments like scalpels , forceps,
-Chemical liquid such as paraffin fats, glycerol ,oil, and glove powder etc.-
7. MOIST HEAT
1. Below 100˚C- Pasteurization
2. At 100˚C- Tyndallization
3. Below 100˚C- Autoclave
1. Pasteurization (below 100◦C)
Method used for control of microorganisms from
beverages like fruit and vegetable, juices,
beer, and dairy products, such as milk.
o Holder method (63°C for 30 mins).
o Flash method (72°C for 20 seconds followed by
rapid cooling to 13° or lower).
8. 2. Tyndallization (At 100◦C)
• Involves steaming at 1000C for 20minutes for 3 consecutive days.
• Used for sterilization of
-gelatin and egg,
-serum or sugar containing media.
9. 3.Autoclave (Above 100◦C)
Principle of Autoclave:
• Autoclave functions similar to a pressure cooker and follows the general laws of gas.
• Water boils when its vapour pressure equals that of the surrounding atmosphere.
• When the atmospheric pressure is raised, the boiling temperature is also raised.
Temperature- 121⁰C for 15 minutes at pressure of 15 psi.
Material Sterilized-
• Surgical instruments
• Culture media
• Autoclavable plastic containers
• Plastic tubes and pipette tips
• Solutions and water
• Biohazardous waste
• Glassware (autoclave resistible).