STAINING, PRACTICAL AND THEORETICAL 



5. Embed in paraffin wax. 



Note: Pyridine may be used in place of alcohols and xylol. 



6. Cut sections at 5/^ and fix them to slides. 



7. Dewax paired sections on slides labelled " A " and " B ". 



8. Treat both sections with absolute alcohol. 



9. Rinse both sections in 95% alcohol, then: 



Take section " A " through steps 10-18, below. 

 Take sections " B " directly to step 18, below. 



10. Rinse in 70% alcohol. 



1 1 . Wash in distilled water. 



12. Oxidize in solution C for one to two minutes until the 

 sections turn a brownish colour. 



Note: This solution should be changed frequently. 



13. Rinse well in distilled water. 



14. Decolorize in solution D for two minutes, 



15. Wash in running tap water for five minutes. 



16. Rinse in 70% alcohol. 



17. Rinse in 95% alcohol. 



18. Place sections " A " and sections " B " in solution F for 

 four to five hours at 50-55° C. 



19. Rinse quickly in 95% alcohol. 



20. Impregnate in solution I for five minutes at 50-55° C. 



21. Rinse quickly in 95% alcohol. 



22. Reduce in solution J for two minutes. 



23. Wash in distilled water. 



24. Tone in solution K until the sections turn greyish. 



25. Fix in solution L (sodium thiosulphate) for two minutes. 



26. Wash in tap water. 



27. Counterstain lightly in 1% eosin or erythrosin. 



28. Dehydrate and clear. 



29. Mount in D.P.X. or Clearmount or Cristalite or neutral 

 Canada balsam in xylol. 



Results: 



The lipofuscin granules appear as small distinct black dots, 

 surrounded by a clear zone, in all sections impregnated without 

 previous oxidation in silver diammine. 



In all sections impregnated with silver diammine after initial 

 oxidation, the granules appear as black rings with clear centres. 



416 



