MICROSCOPIC STUDY AND STAINING 125 



Then rinse in water, dry, and mount. 



This method, while rapid and very convenient, is not so reliable as the 

 Ziehl-Neelson method. 



PAPPENHEIM 's METHOD. 27 The method of Pappenheim is devised 

 for the purpose of differentiating between the tubercle bacillus and 

 the smegma bacillus. Confusion may occasionally arise between 

 these two microorganisms, especially in the examination of urine 

 where smegma bacilli arc derived from the genitals, and less fre- 

 quently in the examination of sputum where smegma bacilli may 

 occasionally be mixed with the secretions of the pharynx and throat. 



Preparations are smeared and fixed by heat in the usual way. 



Stain with hot carbol-fuchsin solution for two minutes. 



Pour off dye without washing and cover with the following mixture: 



Corallin (rosolic acid) 1 gm. 



Absolute alcohol 100 c.c. 



Methylene-blue added to saturation 



Add glycerin 28 20 c.c. 



This mixture is poured on and drained off slowly, the procedure being 

 repeated four or five times, and finally the preparation is washed in water. 

 The combination of alcohol and rosolic acid decolorizes the smegma bacilli, 

 but leaves the tubercle bacilli stained bright red. 



BAUMGARTEN'S METHOD. 29 This method is recommended by the 

 author for differentiation between the bacillus of tuberculosis and 

 the bacillus of leprosy and depends upon the fact that the tubercle 

 bacillus is less easily stained than Bacillus leprse. 



Smears are prepared and fixed by heat in the usual way. 



Stain in dilute alcoholic fuchsin for five minutes. 



Decolorize for twenty seconds in alcohol, ninety-five per cent, ten parts, 

 nitric acid one part. 

 Wash in water. 



Counterstain in methylene-blue. 

 Wash in water, dry, and mount. 



27 Pappenheim, Bcrl. klin. Woch., 1898. 



28 The glycerin is added after the other constituents have been mixe<L 

 Baumgarten, Zeit. f. wissensch. Mikrosk., 1, 1884. 



