Sterilization and Disinfection Methods Quiz

Heat and Sterilization

• Heat contributes to sterilization by denaturing proteins, disrupting cell membranes, and coagulating enzymes, ultimately killing microorganisms.
• The main purpose of sterilization is to completely eliminate or remove all microorganisms, including spores, from an object or fluid.

Methods of Sterilization

• For heat-sensitive fluids like serum and antibiotics, the filtration method is used for sterilization.
• Incineration is used for sterilization by destroying microorganisms through high-temperature burning.
• The method of flaming involves slowly passing an object through a Bunsen flame to reduce the number of microorganisms.
• Radiation is used for sterilization by causing denaturation of proteins and enzymes, leading to microbial death.
• The method of dry heat sterilization, also known as hot air oven, involves exposing objects to heat until they become red hot.
• Irradiation involves exposing objects to radiation to cause denaturation of proteins and enzymes, leading to microbial death.

Thermal Death Time and Temperature

• The thermal death time for sterilization at 180°C is not specified.
• Pasteurization of milk using the holding method requires a temperature of 63°C for 30 minutes.
• Flash autoclaving requires a temperature of 121°C.
• Moist heat is more effective in killing bacteria, their spores, fungi, parasites, and viruses.

Thermal Death Point and Time

• The thermal death point for complete killing of bacteria using moist heat is 121°C, and the time is 15 minutes.

Autoclave Indicators

• An autoclave indicator, such as a biological indicator, is used to ensure that the sterilization process has been effective.

Steaming and Moist Heat

• Steaming as a method of sterilization requires a temperature of 100°C for 30 minutes.
• The most common form of application of moist heat, but not capable of killing endospores or all viruses, is pasteurization.