14 MANUAL OF MICROBIOLOGICAL METHODS 



ene blue solutions are much more selective, vrith special affinity for 

 metachromatic granules. The rose bengal solution is much less com- 

 monly used; it is specially valuable when mucus or colloidal organic 

 material is present, as such material is not ordinarily stained by it. 



GENERAL BACTERIAL STAINS—ALTERNATE PROCEDURES 

 Kinyoun^s Carbol Fuchsin 



Basic fuchsin (dye content not specified; probably 90 %) 4 g 



Phenol crystals 8 g 



Ethyl alcohol (95 %) 20 ml 



Distilled water 100 ml 



This formula is preferred in some quarters to the Ziehl carbol fuchsin. It is attrib- 

 uted to Kinyoun, but the reference to its original publication has not been located. 



Carbol Crystal Violet (Nicolle) 



Original statemeiit of formula Emended statement 



Solution A 



Sat ale gentian violet 10 ml Crystal violet (90 % dye content) 0.4 g 



1 % aqu sol phenol 100 ml Ethyl alcohol (95 %) 10 ml 



Solution B 



Phenol 1 g 



Distilled water 100 ml 



Mix solutions A and B 



This formula is sometimes preferred either as a general stain or in the gram technic. 

 If properly prepared it is permanent, but it has a tendency to gelatinize if the amount 

 of dye is too great. To prevent this sort of deterioration the quantity of dye in the 

 above amended formula has been reduced to 0.4 g from the 1.0 g recommended pre- 

 viously. Even when the solution is so prepared as to be permanent, however, it 

 seems to have no advantage over the ammonium oxalate crystal violet given above. 



Anilin ''Gentian Violet'' (Ehrlich) 



Original statement of formula Emended statement 



Solution A 



Sat ale sol gentian violet 5-20 ml Crystal violet (90 % dye content) 1.2 g 



Anilin water (2 ml anilin shaken Ethyl alcohol (95 %) 12 ml 



with 98 ml water and filtered) 100 ml Solution B 



Anilin 2 ml 



Distilled water 98 ml 



Shake and allow to stand for a few min- 

 utes, then filter. 



Mix solutions A and B 



This formula is given largely for its historic interest. It is a quite unstable solution 

 and has no special value today. It was, however, one of the first important bacterial 

 staining fluids and was formerly regarded as the standard formula for the gram stain. 

 It is not, however, certain what was the "anilin gentian violet" originally employed in 

 the gram stain, even though ascribed to Ehrlich. As a matter of fact Ehrlich seems to 

 be properly credited only with the idea of using anilin water in the formula, as he 

 apparently did not recommend any one definite formula. 



