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Renin Angiotensin Mechanism.

An Introduction to Sterilization.

 

Introduction:

  • Definition: Sterilization is defined as complete removal of microorganisms from an object, surface or a product.

Objectives:

  1. Prevent contamination.

  2. Prevent transmission of pathogenic microorganisms.

  3. To prevent decomposition and spoilage of food and food products.

  4. To prevent contamination of pure cultures from unwanted microorganisms.

  5. To prevent entry of unwanted microbes in microbiological experiments.

  6. To prevent contamination of industrial processes like vitamin, antibiotics, enzymes production etc.

  7. To avoid contamination of the aseptic areas.

Commonly used terminologies:

  1. Sterilization is a process by which a surface, product or an object is completely freed from the microorganisms in vegetative as well as spore form.

  2. Disinfection: Is a process of complete removal of microbes from an inanimate object.

  3. Antiseptic: The substances which are applied on body tissues either to kill the microbes or to stop the growth of microbes.

  4. Germicide: Any substance which kills the vegetative form of the microbes without necessarily killing the spores.

  5. Microbiostasis: It is a process in which growth of the microbes is inhibited but not necessarily killing them.

  6. Preservative: Achemical substance added to food and pharmaceutical products that prevent growth of microbes.

  7. Sanitization: It is a process in which pathogenic microorganisms are killed or made ineffective.

Methods of Sterilization:

  1. Physical Methods:

    1. Dry heat sterilization:

      1. e.g.Incineration, direct flame, red heat, hot air etc.

    2. Moist heat sterilization / steam distillation:

      1. E.g. Pasteurization, Tyndallization, Autoclaving etc.

    3. Filtration / Mechanical Methods:

      1. E.g. Seitz filter., Sintered glass filter., Filter candles, Membrane filters.

    4. Radiation / Cold Sterilization:

      1. Use of Ultraviolet Rays: e.f. UV Light.

      2. Use of ionising radiations: e.g. X Ray, Gamma Rays, Beta Rays.

  2. Chemical Methods:

    1. Gaseous Sterilization:

      1. e.g. Formaldehyde, Ethylene oxide etc.

    2. By using Disinfectants:

      1. e.g. Cresol, Phenol, etc.

Commonly asked Questions:

  1. Define “Sterilization”. List different methods used for sterilization with appropriate examples.

  2. Define the terms: Sterilization, Disinfection, Sanitization, Antiseptic, Disinfectant, Preservative.
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