Transcript Slide 1
* Sterilization: Complete destruction of all transmission m.o (bacteria ,virus) * Disinfection: remove only organisms that cause disease. Sterilization 1)Physical method: a) temperature: 1-Autoclave: - steam heat to 121c at 1.5 atmospheric pressure for 15 min - autoclave treatment will inactivate all fungi, bacteria, viruses and also bacterial spores( quite resistant) 2) Other heat methods: * Flaming: done to inoculating loops and needles * Boiling: boiling water for 15 min (it is unsuitable for sterilization) - not effective against many bacteria and spores * Dry heat: used for sterilization of glass wears - oven is used in dry heat - can be used on powders and other items that effected by steam ( doesn’t cause rusting for the steals) 2) chemical treatment: * Ethylene oxide gas : - used to sterilize objects that cannot survive temp. more than 60 for 3hrs(plastics,optics) - ethylene oxide penetrate the objects and sterilize it (paper ,clothe ,plastic) * Bleach : (use in the house and hospitals) - kill many organisms but it need 20min for full sterilization - it can kill many spores but also ineffective against resistant spores - cause rust for stainless steel * The dry sterilization : - Dry sterilization condition process(DSP) used for sterilization of plastics bottles in beverage industry - used hydrogen peroxide (30-35% con.) under vacuum condition *Ozone: - - sterilize water,air,and disinfectant for surfaces 3) Filtration : -used to remove microbes from solution that cannot treated in other fashion ( heat sensitive compounds such as antibiotics and vitamin) - filtration uses membrane with small pores prevent the microbes passage - cannot remove the virus (why?) 4) Radiation : -used x-rays, Gama rays, subatomic particles - Gamarays penetrate materials used for sterilization of medical package and equipment - ultraviolet (u.v) rays don’t penetrate materials used for sterilization of surfaces , air , iculating cabinate,operating theater)