LABORATORY BACTERIOLOGY 
EXERCISE I 
CLEANING GLASSWARE 
1. It is necessary that the glassware employed should be 
horoughly cleaned before it is used. Several special methods 
ave been suggested for this purpose, but the one frequently 
‘mployed by chemists seems to be the most easily handled 
ind quite as efficient for general use as the more elaborate, 
pecialized processes. It consists in applying the chromic 
cid cleaning mixture after washing the tubes and flasks with 
vater. Experience has taught that usually this method may 
ve abandoned, as a strong alkali is quite sufficient to clean 
he ordinary glassware. It is sometimes necessary to employ 
nore.special methods for cover glasses which are to be used 
n staining bacteria where a mordant is required. Only one 
if these special methods will be given here. 
2. Work for this exercise. Clean all the glassware, test 
ubes, fermentation tubes, flasks, Petri dishes, and reagent 
iottles assigned. 
If the next laboratory period occurs on the following day, 
lace the flasks and test tubes in the incubator to insure their 
reing dry before they are plugged. 
Put the slides and cover glasses in the cleaning mixture ; 
hey can be rinsed and wiped later. 
Read the laboratory maxims. 
3. Methods to be followed in cleaning the different appa- 
atus. (@) Zest tubes. Wash the tubes carefully with a strong 
Ikali soap and water, using the test-tube brush. Rinse the 
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