STAINING, PRACTICAL AND THEORETICAL 



5. Oxidize, in a freshly prepared mixture consisting of equal 

 volumes of solutions A and B, for two to four minutes. 



6. Decolorize with solution C. 



7. Stain the nuclei, in the haematoxylin solution, for five to 

 ten minutes. 



8. Wash and then differentiate in solution E. 



9. Rinse well, in running tap water, to remove the acid. 



10. Stain cellular granules in solution F for five minutes. 



11. Wash in running tap water. 



12. Differentiate in 95% alcohol for one to three minutes, 

 controlling at intervals by microscopic examination. 



13. Dehydrate rapidly with absolute alcohol; clear in xylol; 

 mount in Canada balsam in xylol, or in a neutral synthetic medium 

 such as D.P.X., Cristalite, Clearmount, or Emexel. 



Technique 2 



For pancreatic islets 



Proceed as in the above technique, but with the following 

 modifications : 



Step 5. Oxidize for only one half to one minute. 



Step 7. Increase the staining time to one hour. 



Step 10. Increase the staining time to 10-15 minutes. 



Step 12. Differentiate for three to five minutes. 



Results: 



Basophilic cells of the hypophysis stain a deep blue. Eosino- 

 philic cells: carmine red. Chromophobe cells: grey. The greyish 

 black chromatin structures of the nuclei are brought out with 

 exceptional clarity. Erythrocytes are orange. Fuchsinophil 

 colloid: carmine red. Fuchsinophobe colloid: greyish blue. 

 Connective tissue: dark blue. 



In pancreas, the protoplasm of the external epithelial secretory 

 cells is greyish blue. The zymogen granulation: carmine red (or 

 orange in some experimental animals). Alpha cells of the islets 

 are either bright red or orange, and the beta cells are dark blue. 

 In the different experimental animals, the granulations of the 

 islet cells are stained various shades of red and the blue colour 

 respectively, but the two types of cells are always easy to differ- 

 entiate. 



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