6 BACTEEIOLOGY OF THE EYE 



Loffler's Methylene Blue. To 100 c.cm. water containing 1 c.cm. of a 1 per 

 cent, solution of caustic potash, add 30 c.cm. saturated solution of methylene blue. 

 The solution and the stain are comparatively permanent, and have the advantage 

 of not overstaining and usually showing up details in cells and bacteria. The 

 granules in B. diphtherice and polar bodies are also well shown. Preparations 

 should be stained for one-half to two minutes. (This stain is less suitable for 

 microphotography than fuchsin.) 



Fuchsin. To 10 c.cm. distilled water add 10 to 20 drops of Ziehl's 1 carbol 

 fuchsin ; stain from a few seconds to one minute. If stained intensely differentiate 

 by weak acetic acid, and then freely wash with water. 



A method which can be thoroughly recommended is to make such 

 a simple stained preparation along with a Gram-stained one ; the 

 former can then be examined in water (add 1 drop, and then cover ; 

 soak up the surplus so that the cover-glass does not float). Details, 

 especially capsules, are thus made very evident ; and if it is desired 

 to mount the preparation permanently, add a little water to remove 

 the cover, then dry and mount in balsam. 



Many mixtures of dyes and double stains can be recommended for 

 contrast staining of cell bodies and bacteria, especially when looking 

 for Gonococci. 



We can mention the Pick-Jacobson method : 



Methylene blue (sat. alcohol sol.) ... ... ... 8 drops 



Carbol fuchsin ... ... ... ... ... 15 ,, 



Aq. dist. ... ... ... ... ... 20 c.cm. 



This stains bacteria dark blue, cell nuclei light blue, protoplasm and mucin red. 

 C. Frankel recommends 45 to 50 drops of carbol fuchsin instead of 15, and stains 

 for five minutes, when the nuclei also stain red, and only the bacteria appear dark 

 blue. This modification of Frankel gives beautiful preparations. 



Nicolle's thionin stain is rightly recommended by Morax for organisms which 

 stain badly, especially the Koch- Weeks bacillus ; it consists in staining for one -half 

 to one minute in 



Thionin, sat. sol. in 50 per cent, alcohol ... ... 10 parts 



1 per cent, watery sol. of carbolic acid ... ... 100 ,, 



The nuclei stain blue, the bacteria reddish. The contrast is good and permanent. 



Besides these simple and mixed aniline stains there is Gram's stain. 

 This is the most useful of all, and for clinical diagnosis is by far the 

 most important, for it gives at once a large number of differential 

 diagnoses. By using a suitable contrast stain the Gram-negative 

 organisms and the other histological elements can be readily denned. 

 I will therefore consider this method more fully. 



The technique which I have used for years is that described by 

 Jadassohn : 



1 Fuchsin, 1 ; absolute alcohol, 10 ; phenol, 5 ; distilled water, 100. 



