Laboratory Safety 



B. Contaminated Materials 



1. Perform any procedure that involves a potentially viable antigen very cautiously. 



a. Fix impression smears of fresh tissue in lO'r Fonnalin. 



b. A heat-fixed smear may still contain a viable organism; therefore discard 

 most stained microscope slides into a pan of disinfectant for autoclaving. 



c. After staining, autoclave the rinse buffers and the towel onto which a 

 direct immunofluorescence slide is drained. 



2. Decontaminate work surfaces after processing or otherwise handling potentially 

 infectious materials. 



3. Immediately cover any spilled culture or specimen with Clorox® at 500 ppm. 

 Disinfect counter tops in work areas with an Environmental Protection Agency- 

 registered phenol-base disinfectant. If the culture contained a toxin. Hood with 1 N 

 NaOH to neutralize the toxin. 



4. Autoclave all glassware, laboratory wastes, animal bedding cages, and other poten- 

 tially contaminated items before discarding or recycling. 



Place discard material in a leak-proof pan with a loosely fitting cover; add approx- 

 imately I in of water to the pan and autoclave for I h. If bio-bags are used, fill them 

 only half-way, add a small amount of water, and leave tops open for air exchange 

 during autoclaving. 



5. When an experimental animal is to be discarded, autoclave it before it is incin- 

 erated. 



C. Lyopliilized Cultures 



Most of the reference cultures obtained from the Center for Disease Control (CDC) are 

 lyopliilized and sealed under vacuum. Do not remove the top or release the vacuum before 

 reconstituting them. Perform work in a biological safety cabinet. 



1. Reconstitute the lyophilized culture by aseptically injecting 1.0 ml of sterile 

 distilled water through the rubber stopper with a sterile needle and syringe. 



2. Without removing the needle and syringe, swirl the vial to resuspend the contents. 

 Invert the vial, and withdraw the cell suspension while holding a cotton pledget at the 

 top of the vial to prevent an aerosol or puncture as the needle is withdrawn through 

 the stopper. 



3. Transfer the cell suspension to a small sterile test tube. (Insert a disposable needle 

 through the top of the vial and autoclave before discarding.) 



4. Treat the cell suspension with caution-these are viable organisms. Plate the sus- 

 pension immediately on the recommended agar media. 



D. Fluorescence Equipment with Mercury Arc Lamps 



1. Make certain that power packs for mercury arc lamps are electrically grounded. 



2. Never open the lamp housing on mercury arc equipment while bulb is burning or 

 hot. 



3. Always have a glass filter in place before looking into the microscope. 



135 



