STAINING, PRACTICAL AND THEORETICAL 



B. Sulphuric acid, 5% aqueous 



C. Solution A . . . . • • 47'5 ml. 

 Solution B . . . . • • 3 ml. 

 Distilled water .. .. ..49-5 ml. 



D. Sodium metabisulphite, 3% 



aqueous 



E. Gomori's chrome alum haematoxylin 



F. Alcohol, 70% 99 ml. 



HCl, cone. . . . . . . I ml, 



G. Phloxin, 0-5% aqueous 



H. Phosphotungstic acid, 5% aqueous 



Technique: 



1. Fix pieces of tissue in Bouin or Formalin-Zenker, and embed 

 in paraffin wax. 



2. Cut sections no thicker than 4^11 and fix them to slides. 



3. Dewax with xylol. 



4. Pass through the usual graded alcohols into water. 



5. Post-fix in Bouin for twelve to twenty-four hours. 



6. Wash sections thoroughly in tap water until excess picric acid 

 is removed. 



7. Immerse in solution C for about one minute. 



8. Decolorize with solution D. 



9. Wash in water. 



ID. Stain in the haematoxylin for ten to fifteen minutes, con- 

 trolling by microscopic examination at intervals until the beta 

 cells are prominent, stained blue. 



11. Differentiate in solution F for about one minute. 



12. Wash in running tap water until the sections are clear blue. 



13. Counterstain with the phloxine solution for five minutes. 



14. Rinse in tap water. 



15. Immerse in the phosphotungstic acid solution for one 

 minute, 



16. Wash in running tap water for five minutes, when the 

 sections should regain their red colour. 



17. Differentiate in 95% alcohol: if the section is overstained 

 with the phloxine and the alpha cells do not stand out clearly, 

 rinse for a few seconds in 80% alcohol. 



18. Dehydrate with absolute alcohol. 



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