SOLUTIONS AND STAINS 



27 



GRAM'S IODIN SOLUTION. 



lodin i . o gram 



Potassium iodide 2.0 grams 



Distilled water 300 . o c.c. 



Decolorize with 97 per cent, alcohol until no further traces 

 of the stain can be washed out of the preparation. This takes 

 usually thirty seconds to two minutes, according to thinness 

 of preparation. Wash in water. 



Counterstain with an aqueous contrast stain, preferably 

 Bismarck brown or safranin. 



Sterling's Modification of Gram's Method. Two c.c. anilin 

 oil and 10 c.c. 95 per cent, alcohol. Shake and add 88 c.c. 

 distilled water. Five grams of 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. 



CLASSIFICATION or THE MOST 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 counterstain.) 

 Meningococcus 

 Gonococcus 



Micrococcus catarrhalis 

 Bacillus coli 

 Bacillus dysenterise 

 Bacillus typhosus 

 Bacillus paratyphosus 

 Bacillus fecalis alkaligenes 

 Bacillus enteritidis 

 Bacillus proteus 

 Bacillus mallei 

 Bacillus pyocyaneus 

 Bacillus influenzas 

 Bacillus mucosus capsulatus 

 Bacillus pestis 

 Bacillus maligni edematis 

 Spirillum choleras 

 Bacillus Koch-Weeks 

 Bacillus Morax-Axenfeld 



