STAINING TUBERCLE BACTERIA (BACILLI) 65 
Sudan III is reported by Dorset to be a very good differen- 
tial stain for this organism. A saturated solution in 80% alco- 
‘hol is used. It is reported to be effective in differentiating the 
tubercle organism from that of leprosy and from the smegma 
bacillus. 
Fontes method of staining tubercle bacteria. (@) Stain 
the preparation with ordinary carbol fuchsin for from 5 to ro 
minutes, applying heat. 
-(6) Wash in tap water. 
(¢) Stain about 2 minutes with carbol gentian violet. 
(@) Treat with Lugol’s solution until no more metallic 
mirrors are formed (decolorization is more easily effected if 
at this point the preparation is blotted thoroughly). 
(¢) Treat with acetone alcohol (equal parts of alcohol and 
acetone). Wash until the stain ceases to wash out. 
(/) Wash in distilled water. : 
(g) Counterstain with methylene blue. 
Cent. f. Bakt. r. Abt. Orig., Feb. 26, 1909. 
Herman’s method of staining tubercle bacteria. Stain the 
preparation for from 5 to 10 minutes, using heat. Herman 
employs a stain composed of a mixture of 3 parts of a 1% 
ammonium carbonate solution and 1 part of a 3% crystal 
violet solution in 96% alcohol. The preparations are stained 
in this from 5 to 10 minutes, using heat. + 
They are then decolorized for several seconds in 10% nitric 
acid, and then in 96% alcohol. 
The tubercle bacteria will be stained a brilliant violet. 
Cent. f. Bakt. 1. Abt. Orig., Bd. 60. S. 600. 
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