172 Medical Bacteriology. 
EXERCISE CV. STAINING SECTIONS. 
GENERAL HISTOLOGICAL METHOD. 
Hematoxylin and Eosin. 
a. Transfer sections from alcohol to distilled water. 
; db. Stain in alum-hematoxylin 2, 5 to 30 minutes. The stain may be prepared as 
follows (Boehmer): 
1. Hematoxylon erystals, - - - - - - 1 gram. 
Absolute alcohol, - - - - - - - 10ce. 
2. Alum, - - - - - - - - 20 grams. 
Distilled water, - - - - - - - 200 ec. 
Cover the solutions and allow them to stand over night. The next day mix them 
and allow the mixture to stand for one week in a wide-mouthed bottle lightly plugged 
with cotton. Then filter into a bottle provided with a good cork. The solution is now 
ready for use but its staining powers improve with age. 
c. Wash the sectionsin several changes of water until they have lost all traces of a 
red tint. 
d. Counter-stain with eosin (jy to + % in 60 % alcohol) 1 to 5 minutes. 
e. Alcohol, 95 %, two or three changes to dehydrate and remove excess of counter: 
stain. 
f. Clear in oil of origanum or Dunham’s mixture, white oil of thyme 4 parts, oil 
of cloves 1 part. 
GENERAL BACTERIOLOGICAL METHODS. 
A. Loeffler’s Universal Method. 
a. Take sections out of alcohol into Loeffler’s methvlen blue for 5-30 minutes. 
b. Decolorize in acetic acid (0. 1%) 10 to 20 seconds. 
c. Dehydrate in absolute alcohol, two or three changes, a few seconds. 
d. Clear in xylene. 
e. Mount in balsam. 
B. Weigert’s Method. 
a. From aleohol to Ehrlich’s waitin water gentian violet 5-15 minutes. 
b. Wash in 0. 6% salt solution. 
c. Dry with filter paper. 
d, Place in potassium iodide and iodine solution (iodine 1 part, potassium 
iodide 2 parts, water 100 parts). 
e. Dry with filter paper. 
J. Decolorize in a mixture of anilin oil 2 parts and xylene 1 part, 2-5 minutes. 
g. Clear in xylene. 
h. Mount in balsam. 
This stain can only be used with those organisms which take the Gram stain, namely: 
S. pyogenes, M. pyogenes, M. aureus, Sar. tetragena, B. anthracis, B. pneumoniae, B. 
rhusiopathiae, B. tuberculosis, B. leprae, B. diphtheriae, P. aeruginosa, B. Welchii, B. 
chauvaet, B. oedematis, B. tetani and Strevtothrix actinomyces. 
