Page 22 - MNU PM502 Ph. Micreo practical

Pharm D- Clinical Pharmacy Program Third Level Pharmaceutical Microbiology& Antimicrobials (PM 502)

8. Types of Material Used: Do not utilize rubber products, textiles, or combustible

or volatile substances in the oven.

9. Maintain Space: Do not overfill the oven. Maintain space for air circulation.

10. Wrapping: Wrap the outside of glassware such as Petri dishes and pipettes well.

Mouths of flasks, test tubes and both ends of pipettes must be plugged with cotton

wool

11. Before opening the door of the hot air oven, cool it to 60 degrees Celsius. It keeps

glassware from shattering.

12. If the door is opened before time, heat escapes and the process becomes

incomplete. Thus, the cycle must be properly repeated all over.

II. Moist Heat:

• Moist heat sterilization is one of the most effective methods of sterilization

where the steam under pressure acts as a bactericidal agent.

• Moist heat sterilization usually involves the use of steam at temperatures in the

range 121–134°C.

• Sterilization can be effectively achieved at a temperature above 100C using an

autoclave. Water boils at 100C at atmospheric pressure. High pressure

increases the boiling point of water and thus helps achieve a higher temperature

for sterilization.

Autoclave:

• An autoclave is a device that works on the principle of moist heat

sterilization through the generation of steam under pressure

• Thus, there are four parameters of steam sterilization: steam, pressure,

temperature, and time.

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