34 ELEMENTARY BACTERIOLOGY LABORATORY EXERCISES 
SECTION 11: ANAEROBIC METHODS 
EXERCISE 50 
ANAEROBIC CULTURE OF BACTERIA 
With the culture of Clostridium welchii inoculate: 
(1) A glucose infusion agar “shake” (Liborius’ method) 
(2) A tube of cooked meat or brain medium 
(3) A glucose agar slope (for Wright’s method) 
(4) A glucose agar slope (for control) 
Melt a tube of glucose infusion agar in boiling water or in flowing steam. 
The heating should be continued for about ten minutes so as to free the medium 
entirely of free oxygen. Cool in the water bath to 45° C. and inoculate. Take 
care not to shake the melted agar or to stir in air in making the inoculation. Place 
the inoculated tube in cold water to harden. 
Heat a tube of cooked ‘meat or brain medium in the same manner and cool 
to a temperature of 45° C. or below before inoculating. 
Inoculate two glucose infusion agar slopes. Incubate one of those under 
aerobic conditions in the usual way as a control. With the other tube, push 
down the cotton plug about one-half inch below the top of the tube. Fill in the 
space above the cotton with pyrogallol. Pour upon the pyrogallol a small amount 
of concentrated NaOH and close tightly with a rubber stopper. Invert the tube 
and incubate in this position. 
Incubate all the cultures at 37° C. Make observations at the next laboratory 
period. 
