disinfection and sterilization Flashcards
disinfectant slection criteria
- fast acting in the presence of organic substances
- effective against all types of infectious agents without destroying tissue
- easily penetrate material to be disinfecting without damaging or discolouring it
- easy to prepare, stable when exposed to light, heat and other factors
methods of sterilization
dry heat- hot air oven- used for glassware, instruments, paper wrapped articles, oils, waxes and powders- 160 for 2 hrs or 170 for 1 hr
moist heat: autoclave and pressure cooker. used for culture media, water containing materials and lab waste.
incineration: burns and physcially destroys living organsism, inoculating loops and lab waste
filtration: used in media prep , filtering delicate supplements that are inactivated by autoclaving(carbs, antibiotics)
UV- used additionally with other methods, sterilize workspaces and tools, germicidal wavelengths 185nm-265nm.
autoclave temp and time
121 celcius and 15 mins
2 types of autoclaves
porous load autoclaves - modern, fast, reliable efficient, air removed by partial vacuum, admitting steam and reppeating, short cycles
downward displacment autocalve- air removed by dilution in turbulent steam flow, long cycles, inefficient