1.PHYSICAL METHODS OF STERILIZATION - Click here

STERILIZATION

DEFINITIONS:-  Sterilization Sterilization may be defined as any process by means of which all forms of microbial life (bacteria, spores, fungi and viruses) are completely destroyed. The word 'sterile denotes the complete freedom from, or absence of, all living microbes and other forms of life. Disinfection This is any process, chemical or physical, whereby harmful microbial agents are destroyed. 

Disinfection essentially destroys infectious micro-organisms but not necessarily their spores. Disinfection is applied on inanimate objects only. The common disinfecting agents (disinfectants) are chemicals, boiling water, flowing steam and ultraviolet radiation. 

• Disinfectants are bactericidal. Antiseptic Antiseptics are substances which, when used on micro-organisms, will render them inactive by inhibiting their multiplication.
  
• The effectiveness of the antiseptic depends on the character of preparation or the method of application. Antiseptics are bacteriostatic and they can be applied on living tissues.
• Germicide This is any substance that will kill germs or microbes. Chemical agents are employed to kill pathogens but not necessarily their resistant spores; and they are used in solution form on living tissues as well as on inanimate objects.
  
• Other commonly used terms with similar definitions are bactericide, fungicide, viricide and sporicide. Most disinfectants are germicides. Bacteriostate  This is a chemical agent that can inhibit the growth or multiplication of bacteria. Bacteriostatic action is reversible.

Basic Principles of Sterilization

• An important aim of all sterilization and disinfection strategy is to prevent the spread of bacteria.
•  In certain cases, all microbes are regarded as potential pathogens and therefore it is essential to eliminate all forms of microbial life.
  
• All microbiological techniques require appropriate and adequate sterilisation.
• It therefore follows that sterilization of materials and instruments are essential in certain circumstances, while in other situations, disinfection is just adequate.
• The various methods of sterilization are designed to kill resistant spores The vegetative cells can be destroyed with relative ease.

Methods of sterilization can be divided into:

1.PHYSICAL METHODS OF STERILIZATION  - Click here

2. CHEMICAL STERILIZATION - Click here

summary of sterilization methods.

summary of sterilization methods.