Sterilization By : April 2017 Dr.Samia Sadig Mohamed Faculty of Medicine Dept. Microbiology &parasitology April 2017

Aims By the end of the lecture the student should be able to know: The principle and applications of sterilization

Keys Definitions & Sterilization Methods of sterilization

Hands Spread Disease wash me !!!

History Of Sterilization

Definitions : Sterilization: A treatment that kills or removes all living cells, including viruses and spores, from a substance or object

Definitions : Sterilization / Complete Destruction - No degrees of sterilization (All or Nothing)

Filtration Physical Methods Heat Chemical Methods Moist Dry Agent acting on the cell membrane phenols STERILIZATION Agent that denature Proteins Acids Ionizing radiation X-rays, beta rays Gamma rays Heavy metals Ultraviolet rays Oxidizing agents Dyes Filtration Methods of sterilization

Physical Methods Heat Filtration Radiation

Heat Most Frequent and Widely Used. Always Consider 1. Type of Heat 2. Time of Application 3. Temperature Endospores are the most heat resistant of all cells.

Moist Heat Sterilization Boiling Autoclaving

Kills Everything Except Some Endospores Boiling 100° C for 30 Minutes Kills Everything Except Some Endospores

Autoclaving Steam Under Pressure 121° C for 15 Minutes at 15 lb/in2 Heat-labile Substances will be Denatured Steam Must Contact the Material

TEST Of efficiency of autoclave BY (i)Bological: put bacillus spores & see if it die (ii)using chemical that change its colour (iii)physical (digital)

Dry Heat Sterilization Direct Flaming Incineration Hot-Air Sterilization (Oven)

(ALL disposable production.. hospitals &factories…) Incineration Burns Used for a. Needles b. Inoculating Wires c. Glassware (ALL disposable production.. hospitals &factories…)

160° C for 2 Hours or 170° C for 1 hour Used for a. Glassware b. Metal Dry Heat (Hot Air Oven) 160° C for 2 Hours or 170° C for 1 hour Used for a. Glassware b. Metal c. Objects That Won’t Melt

Pasteurization A High Temperature Is Used For a Short Time Batch Method 63 °C for 30 Minutes Flash Method 72 °C for 15 Seconds Ultra-High-Temperature is 140 °C for 3 seconds

Filtration The passage of a liquid or gas through a filter with pores small enough to retain microbes. Especially important to sterilize solutions which would be denatured by heat (antibiotics, injectable drugs, amino acids, vitamins.)

High-Efficiency Particulate Air Filters 1. Operating Rooms HEPA Filters High-Efficiency Particulate Air Filters 1. Operating Rooms 2. Burn Units

Acts By Destroying DNA or Damaging It. Radiation Acts By Destroying DNA or Damaging It. Dependent on the Wavelength, Intensity, and Duration

Radiatio Ionizing Radiation 1. High Degree of Penetration 2. Examples - Gamma Rays - X-rays Ultraviolet Radiation …is used for disinfection operating room . 1. Non ionizing 2. Low Degree of Penetration 3. Harmful / Skin / Eyes

Definitions : Disinfection:Removal or killing many organism…partial …not all Disinfectant : chemical used for disinfection of non living.. Examples :Alcohol:human skin Phenol :Detol 5% Iodine:skin Chlor:Water H2O2:Wound Antiseptec:chemical used for disinfection of living tissue..

? Discuss the Methods of sterilization .

Thanks!