SPECIAL METHODS OF STAINING AND MODIFICATIONS 6 1 



hol with the stain, so that while the section is being anhy- 

 drated, it is constantly supplied with fresh dye. 



Weigert uses anilin-oil to dehydrate instead of alcohol, and 

 here, too, it can be used mixed with the dye. 



Capsule Stain (Buerger). I. Spread culture by means of 

 a drop of ascitic fluid on cover-glass. 



II. Fix in Muller's fluid, which has been saturated with 

 5 per cent, bichlorid of mercury, and warm for three seconds. 



III. Wash quickly in water; rinse in alcohol. 



IV. Cover with tincture of iodin for one minute. 

 V. Wash in alcohol and dry in air. 



VI. Stain in anilin-water gentian-violet for two seconds. 

 VII. Wash in 2 per cent, salt solution. 



VIII. Mount in salt solution ringed with vaselin. 



Hiss' Method for Capsule. Smear on cover-glass the 

 organisms mixed with a drop of animal serum (beef-blood 

 serum or ascitic fluid). Dry in air. Fix by heat. Stain for 

 few seconds in Hiss' stain (p. 52). Wash in 20 per cent, cop- 

 per sulphate solution. Dry and mount. Capsule appears 

 as faint blue halo about dark-purple cell. 



Flagella Stain, with Loffler's Mordant. I. A few drops 

 of the mordant stain (p. 51) are placed upon the spread 

 cover-glass and heated until it steams. 



II. Wash with water until the cover-glass looks almost 

 clean, using a small piece of filter-paper to rub off the crusts 

 which have gathered around the edges. 



III. Anilin-water fuchsin (neutral) held in flame about one 

 and one-half minutes. 



IV. Wash in water. 



If the stain is properly made, the bacteria are deeply 

 colored and the flagella seen as little dark lines attached to 

 them. 



Unna's Method for Fungi. Especially useful for epi- 

 dermic scales. Moisten horny scale or crust with acetic acid; 

 macerate between two glass slides; dry in flame; wash out fat 

 with ether and alcohol (equal parts) ; stain in borax methyl-blue 



