SINGLE STAINS WITH CYTOPLASMIC DYES 659 



Picro-carmin is used as a progressive stain. Since the picric 



acid is soluble in alcohol, dehydration should be rapid, or a crystal 



of picric acid should be added to the alcohol used for dehydration. 



Safranin. This dye is a coal-tar derivative ; it is an excellent 



nuclear stain. Like carmin, safranin yields a deep red color. 



Safranin (Griibler's) 1 grm. 



Distilled water 100 cc. 



1. Tissues taken from water are stained five minutes. 



2. Wash in water. 



3. Dehydrate rapidly in absolute alcohol. The alcohol removes 

 some of the safranin, giving a regressive effect. 



SINGLE STAINS WITH CYTOPLASMIC DYES 



Eosin. This dye is a coal-tar derivative. There are no less than 

 seventeen varieties of the dye on the market, of which five are in 

 general use. These are : (1) yellowish alcoholic ; (2) bluish alco- 

 holic ; (3) yellowish watery ; (4) bluish watery ; (5) pure French 

 eosin. The most reliable of these dyes are manufactured by Griib- 

 ler. The first and fifth varieties are to be recommended as blood 

 stains, the first and fourth are the best for general use. Two dis- 

 tinct methods are based upon this choice of dyes. 



Method I: 



Yellowish alcoholic eosin 1 grm. 



70 per cent, alcohol 100 cc. 



This stock solution is usually diluted with four to ten volumes of 

 70 to 95 per cent, alcohol just before using. The stain is preferably 

 preceded by the use of a nuclear dye, after which the sections 

 should be dehydrated in 95 per cent, alcohol. 



1. Stain in the diluted eosin, one to five minutes, or until the 

 sections become a bright red color. 



2. Wash quickly in absolute alcohol, clear, and mount. The 

 color is dissolved out during this process, producing some differ- 

 entiation by regression. 



Method II: 



Bluish watery eosin 1 grm. 



Distilled water 100 cc. 



The stock solution should be diluted with one to four volumes of 

 distilled water before using. 



1. Tissues are taken from water and placed in the dilute eosin, 

 one to five minutes. 



2. Wash quickly in water to remove the excess of the dye. 



