SECTION TWO 



4. Counterstain in carmalum for three to five minutes. 



5. Rinse in water; mount in glycerine jelly. 



Result: 



Degenerated myelin, blue. 



Reference: Lillie, R. D. (1944). 



SUDAN BROWN 



For fat and for acute fatty degeneration not shown by 



Scarlet R 



Solutions required: 



A. Stock solution of Sudan brown 



saturated in isopropyl alcohol or 

 ethylene glycol 



B. Mayer's acid haemalum. 



Technique: 



1. Fix tissues in 10% 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 or Aquamount. 



Results: 



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

 Reference: Lillie, R. D. (1948), p. 159. 



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