STAINING FLUIDS 29 



i 



of this stock solution may be added to a small dish full of water at 

 the time of using. 



BORAX - CARMINE (GRENACHER) 



Carmine 2.5 grams. 



Borax 4.0 grams. 



Alcohol (70%) 100.0 c.e. 



Water 100.0 c.c. 



Rub the carmine and borax together. Dissolve them in the 

 water, which should be hot. The alcohol may be added when the 

 mixture is cold. The stain will be available after two weeks, but 

 improves with age. This solution is especially suitable for the 

 staining of whole masses of tissue before imbedding, i.e., in bulk. 

 For staining in bulk, leave the tissue in the carmine for twenty- 

 four hours. It may be used for sections, however, which are to be 

 left in the stain fifteen minutes or longer. In all cases carmine 

 staining is to be finished with the use of acid alcohol, which diifer- 

 entiates the elements. 



ACID ALCOHOL 



Alcohol (70%} 100 c.c. 



Hydrochloric acid (strong) 1 c.c. 



Sections stained in carmine are placed in acid alcohol for a few 

 minutes. They acquire a brilliant scarlet color. For specimens 

 stained in bulk, dilute the acid alcohol with twice as much 70 per 

 cent, alcohol, and leave the tissue in the mixture twenty-four hours. 



PICRO- CARMINE 



Carmine 1 gram. 



Aqua ammonia (strong) 5 c.c. 



Water 50 c.c. 



Saturated watery solution of picric acid . . . . 50 c.c. 



Add the picric acid solution after dissolving the carmine in the 

 diluted ammonia. Let the mixture stand uncorked for two days, 

 and filter. The carmine gives a nuclear stain, while the picric acid 

 serves as a counter stain. 



IODINE SOLUTION 



Iodine 1 gram. 



Potassium iodide 2 grams. 



Water . . 300 c.c. 



