MICROSCOPIC STUDY AND STAINING 97 



through a moist filter paper until perfectly clear. A saturated alco- 

 holic solution of either fuchsin or gentian-violet is added to this anilin 

 water in proportions of about one to ten or until a slightly iridescent 

 pellicle appears upon the surface of the solution. 



An extremely useful and very strong staining solution is the Ziehl 

 carbol-fuchsin solution, made up as follows : 1 



Fuchsin (basic) ____ < T^Cl*>. . .VV* .VY^T::*^ ____ 1 gm. 



Alcohol (absolute) ................................... 10 c.c. 



Five per cent carbolic acid ........................... 100 c.c. '' 



To make up this staining solution, mix 90 c.c. of a five per cent aque- 

 ous solution of carbolic acid with 10 c.c. of saturated alcoholic basic 

 fuchsin. . 



It may also be made up as follows: 



Weigh out 



Basic fuchsin ........................................ 1 gram 



Carbolic acid ........................................ 5 grams 



Dissolve in 



Distilled water .......................... ............ 100 c.c. 



Filter and add 



Absolute alcohol .................................... 10 c.c. 



SPECIAL STAINING METHODS 



Spore Stains. ABBOTT'S METHOD. 2 Cover-slips are smeared and 

 fixed by heat in the usual manner. 



Cover with Loeffler's alkaline methylene-blue and heat the stain 

 until it boils, repeat the heating at intervals but do not boil continuously. 

 Keep this up for one minute. 



Rinse in water. 



Decolorize with a mixture of alcohol eighty per cent 98 c.c. and nitric 

 acid 2 c.c., until all blue has disappeared. 



Rinse in water. 



Dip from three to five seconds in saturated alcoholic solution of 

 eosin 10 c.c., and water 90 c.c. 



Rinse in /water, blot, and mount in balsam. 



By this method the spores are stained blue, the bodies of the bacilli 

 are stained pink. 



i Ziehl, Deut. med. Woch., 1882. 2 Abbott, "Prin. of Bact.," Phila., 1905. 



