MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



B. Benzidine base, pure . . . . o-2 gm. 

 Distilled water . . . . . . 200 ml. 



Filter and add 4 drops hydrogen 

 peroxide (20 vols.) to the filtrate; 

 store in a dark bottle. 



C. Safranin . . . . . . . . 1% aqueous 



Technique: 



1. Air-dried blood films are flooded with Solution A for one 

 minute. Pour off ; then without washing and while still wet : 



2. Flood with Solution B and leave for two minutes ; then rinse 

 in tap water. 



3. Counterstain in Solution C for one minute. 



4. Wash with tap water; blot and dry. 



Results: 



Peroxidase granules, blue. Nuclei of leucocytes, orange-red. 



Note: Unmounted specimens keep for many months without 

 fading. 



PICRO METHYL BLUE - EOSIN 

 For urinary casts 



Abstract J. of Lab. & Clin. Med. (U.S.A.), 22, 853, 1937, Jeanette Allen 

 Behre, and William Muhlberg. 



Solutions required: 



A. Eosin yellowish 0-5% aqueous. 



B. Methyl blue I % aqueous .. i ml. 

 Picric acid saturated, aqueous . . 10 ml. 

 Glycerine . . . . . . . . 10 drops 



Technique: 



1. The urine is centrifuged and the supernatant liquid decanted 

 as usual for microscopic examination. 



2. One drop of eosin solution is added to the sediment and 

 mixed by shaking from side to side for one to two minutes. 



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