MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



Technique: 



1. Fix tissues in io% formalin. 



2. Frozen sections are stained for five minutes in a diluted 

 solution of Sudan brown prepared by mixing 6 volumes of the 

 stock solution with 4 volumes distilled water. 



{Note: This diluted solution keeps only for one day, and 

 should, therefore, only be prepared immediately before use.) 



3. Float out in tap water. 



4. Stain for two to five minutes in Mayer's acid haemalum; 

 then rinse in tap water. 



5. Immerse in tap water or in 1% sodium phosphate 

 (Na2HP04) until the section turns blue. 



6. Rinse in distilled water. 



7. Mount in Apathy's gum syrup. 



Results: 



Fat, brown; nuclei, bluish grey; protoplasm, colourless. 



SUDAN 2 

 For degenerating and intact myelin and fat 



Solutions required: 



A. Haematoxylin 1% in absolute 



alcohol, at least one to five days 



old . . . . . . . . 50 ml. 



4% iron alum aqueous . . . . 50 ml. 



This solution should be prepared immediately 



before use. 



B. Borax . . . . . . . . i gm. 1 



Potassium ferricyanide . . • • 5 gni- 



Distilled water . . . . . . 100 ml. 



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