STAINING METHODS 13 



Ammonium Oxalate Crystal Violet {Hucker*s) 



Solution A Solution B 



Crystal violet (90 % dye content) ^ . 2 g Ammonium oxalate 0.8 g 



Ethyl alcohol (95 %) 20 ml Distilled water 80 ml 



Mix solutions A and B 



Crystal Violet in Dilute Alcohol 



Crystal violet (90 % dye content) 2 g 



Ethyl alcohol (95 %) 20 ml 



Distilled water 80 ml 



Loeffler^s Alkaline Methylene Blue 



Original statement of formula Emended statement 



Solution A 

 Cone sol methylene blue in al- Methylene blue (90 % dye con- 



cohol 30 ml tent) 0.3 g 



Sol KOH in distilled water Ethyl alcohol (95 %) 30 ml 



(1 :10,000) 100 ml Solution B 



Dilute KOH (0.01 % by weight) 100 ml 

 Mix solutions A and B 



Methylene Blue in Dilute Alcohol 



Methylene blue (80 % dye content) 0.3 g 



Ethyl alcohol (95 %) 30 ml 



Distilled water 100 ml 



Carbol Rose Bengal 



Rose bengal (90 % dye content) " 1 g 



Phenol (5 % aqueous solution) 100 ml 



CaCh 0.01-0.03 g 



(The amount of CaCh added determines the intensity of staining.) 



Staining schedule: Follow the general procedure given under "Prepa- 

 ration of Smears," page 11, allowing 5-60 sec for application of the stain. 

 Overstaining rarely occurs except with carbol f uchsin ; understaining does 

 not have to be feared except with rose bengal. 



Results: The results depend on which of the above staining fluids is 

 selected. They are listed in the order of intensity of action; i.e., carbol 

 fuchsin gives the most intense stain and is not indicated when selective 

 staining is desired or when much debris is present on the shde. The 

 crystal violet solutions are very good for routine purposes. The methyl- 



^ It is not necessary that dry stains of ine exact dye content specified be used in this 

 or in the preceding and following formulas. Samples of higher or lower dye content 

 may be employed by making the proper adjustment in the quantity used. 



