MICROSCOPIC STUDY AND STAINING 



123 



gentian violet are ground in a mortar and the anilin solution added 

 slowly while grinding. Filter. This solution keeps, and stains in 

 one-half to one minute. 23 



CLASSIFICATION OF THE MORE IMPORTANT PATHOGENIC BACTERIA 

 ACCORDING TO GRAM'S STAIN. 



Gram-positive. 

 (Retain the Gentian-violet.) 



Micrococcus pyogenes aureus 



Micrococcus pyogenes albus 



Streptococcus pyogenes 



Micrococcus tetragenus 



Pneumococcus 



Bacillus subtilis 



Bacillus anthracis 



Bacillus diphtherias 



Bacillus tetanus 



Bacillus tuberculosis and other 



acid-fast bacilli 

 Bacillus aerogenes capsulatus 

 Bacillus botulinus 



Gram-negative. 

 (Take Counter stain.) 



Meningococcus 

 Gonococcus 



Micrococcus catarrhalis 

 Bacillus coli 

 Bacillus dysenteriae 

 Bacillus typhosus 

 Bacillus paratyphosus 

 Bacillus fecalis alkaligenes 

 Bacillus enteritidis 

 Bacillus proteus (proteus) 

 Bacillus mallei 

 Bacillus pyocyaneus 

 Bacillus influenzas 

 Bacillus mucosus capsulatus 

 Bacillus pestis 

 Bacillus maligni oedematis 

 Spirillum choleras 

 Bacillus Koch- Weeks 

 Bacillus Morax-Axenfeld 



Stains for Acid-Fast Bacteria. These methods of staining are 

 chiefly useful in the demonstration of tubercle bacilli. These bacteria 

 because of their waxy cell membranes are not easily stained by any 

 but the most intensified dyes, but when once stained, retain the 

 color in spite of energetic decolorization with acid. For this reason 

 they are known as acid-fast bacilli. The first method devised for 

 the staining of tubercle and allied bacilli was that of Ehrlich. 



23 This is the routine method employed in our laboratory at present. In using 

 Sterling's stain the time of staining can be abbreviated as follows: 



Sterling's Gentian Violet one minute 



lodin thirty seconds to one minute 



