Quick Review Cards for Medical Laboratory Science

Sterilization and Disinfection Clinical Microbiology Review 139

Temperature

Steam under pressure

Boiling

Pasteurization

Hot air sterilization

Incineration

Filtration

Radiation

Chemicals
Alcohols

Chlorine

Formalin

Most reliable

Autoclave. Most practical & dependable method. 15 lb of pressure for 15 min. 121°C. Kills spores.

Not reliable. Spores may not be killed.

Used in food industry to kill foodborne pathogens. Doesn’t sterilize. Liquid is heated to 71.7°C for 15 sec.

Used when steam may damage or fail to penetrate. 2 hours at 170°C. Kills spores.

Used to sterilize inoculating loops & biomedical wastes.

Used to sterilize liquids that are thermolabile (e.g., urea broth). HEPA air filters are used in BSC.

UV light. Used in BSC.

Ethyl & isopropyl (70%–80%) frequently used as antiseptics & disinfectants. Don’t kill spores.

Sodium hypochlorite (household bleach). One of most effective agents against HIV & HBV. 10% solution.

Prepare daily.

Aqueous solution of formaldehyde. 5%–10% formalin used to preserve & fix specimens. Exposure must be

monitored.

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