32 BACTERIOLOGY 



3. Add anilin water gentian violet solution (4) repeatedly 

 until the acid is removed. 



4. Wash briskly in a 2 per cent solution of common salt. 



5. Mount in salt solution and examine. 



For further directions on the staining of bacteria see p. 6. 



Spore Staining, Abbot's Method 



1. Stain cover-flass preparation with Loffler's methylene 

 blue (3), heating repeatedly until staining solution boils, but not 

 continuously, for one minute. 



2. Wash in water. 



3. Wash in 95 per cent alcohol containing 0.2-0.3 per cent 

 of hydrochloric acid. 



4. Wash in water. 



5. Stain 8-10 seconds, with anilin-water fuchsin (4). 



6. Wash in water and mount. 



Ehrlich's Method for Tubercle Bacilli 



1. Stain cover-glass films, 5-10 minutes, cold, with Ehrlich's 

 anilin water fuchsin, or gentian violet (4). 



2. Wash in water. 



3. Decolorize in 20 per cent nitric acid, one-half to one 

 minute. 



4. Wash in 70 per cent alcohol until no more color is given 

 off ; dry, and mount. 



Ziehl-Neelsen-Gabbet Method for Tubercle Bacilli 



1. Stain cover-glass films, 5-10 minutes, cold, with Ziehl's 

 carbol-fuchsin (5). 



2. Decolorize for one minute with Gabbet's methylene blue 

 solution (6). 



4. Wash in water ; dry, and mount. 



