EnrichedMedia, SelectiveMedia, DifferentialMedia，combination selective anddifferential media
第2页：2Sterilization–destr
2 Sterilization–destruction of all forms of microbial life,including endospores.Physical Methods—Moist heatAutoclaving
Action-protein denaturation.
Very effective method of sterilization; atabout 15 psi（Ib/in2）of pressure (121ºC[ 250ºF]), all vegetative cells and theirendospores are killed in about 15 min.
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第4页：
第5页：—DryheatDirectflaming
—Dry heatDirect flaming
example: Inoculation loopHot-air sterilization
Baking in oven
Very effective method of sterilization,but requires temperature of 170ºC[ 340ºF]for about 2 hr.
第6页：—Filtration
—Filtration
–Separation of bacteria from suspending liquid.
–Removes microbes by passage of a liquid orgas through a screen like material. Most filtersconsist of diatomaceous earth, cellulose acetateor nitrocellulose.
–0.45
m filters removes most bacteria,
0.20
m more inclusive, viruses need 0.01
m.
–Useful for sterilizing liquids (enzymes, vaccines)that are destroyed by heat.
