REPORT OF COMMITTEE ON DESCRIPTIVE CHART 



PART III. A MODIFICATION OF THE GRAM STAIN 



KENNETH N. ATKINS 

 Dartmouth Medical School 



The aniline gentian violet staining solution of the Gram stain 

 is not stable, usually becoming obviously decomposed in a few 

 weeks. One is occasionally apt to use a stain which is too old 

 to give accurate results. The diversity of procedure in using 

 this stain, as noted in textbooks of bacteriology, is doubtless an 

 outgrowth of attempts to make the stain more useful and con- 

 sistent in its action. The use of a stable staining solution would 

 tend towards uniformity of procedure and accuracy of results. 

 The writer does not wish to introduce a new stain, to be used in 

 place of the Gram stain (Gram, 1884), but rather, to modify 

 that well known stain so that it will be stable while its chemical 

 properties remain unchanged. 



The stain is as follows: 



Staining solution 



Saturated 95 per cent alcohol solution gentian violet 1 part 



Aniline sulphate, 1 per cejit aqueous solution 3 parts 



Iodine solution 



Iodine 2 grams 



Normal solution sodium hydroxide 10 cc. 



Water 90 cc. 



'(Dissolve the iodine in the sodium hydroxide solution and add the water.) 



Decolorizing solution 

 Alcohol 95 per cent 



Technique 



The slide is prepared as usual and stained for one minute. Wash briefly to 

 remove the excess of stain and apply iodine solution for one minute. 



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