MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



B. Picric acid saturated aqueous. 



C. Stirling's gentian violet. 



D. Gram's iodine. 



E. Equal volumes of xylol and aniline oil. 



Technique: 

 Tissues should be fixed in Helly and embedded in paraffin wax. 



1. Stain for ten to thirty seconds in Solution A; then wash in 

 tap water. 



2. Differentiate for a few seconds in formaUn till the bright red 

 colour changes to a clear deep pink ; then wash with tap water. 



3. Counterstain one to five minutes in Solution B until the sec- 

 tion appears purplish yellow to the naked eye ; then wash with tap 

 water. 



4. Differentiate in 95% alcohol until the section appears red; 

 then wash in tap water. 



5. Stain for about five minutes in Solution C; then wash in tap 

 water. 



6. Stain for one minute in Solution D ; then, without washing, 

 blot dry. 



7. Treat in Solution E until no more colour comes out. 



8. Pass through two changes of xylol; then mount. 



Results: 



Gram-positive organisms, blue. Gram-negative, red. Tissues, 

 varying shades of red and purple. 



MALLORY'S STAIN - HAEMATOXYLIN 

 For the differential staining of the pancreatic islets 



Solutions required: 



A. Distilled water . . . . . . 100 ml. 



Sulphuric acid cone. . . . . i ml. 



Potassium Permanganate . . . . i gm. 



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