MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



Technique: 



1. Pieces of tissue are fixed in Zenker; washed; then trans- 

 ferred to a mixture of Lugol's iodine and 80% alcohol (equal vol- 

 umes of each) for six to twenty-four hours. 



2. Transfer to 80% alcohol for twelve to twenty-four hours. 



3. Immerse in 95% alcohol for two to six hours. 



4. Transfer to a mixture consisting of equal volumes of absolute 

 alcohol and xylol, for half an hour. 



5. Immerse in xylol for half an hour. 



6. Immerse in two changes of paraffin wax before casting the 

 block and finally sectioning. 



7. Fix sections to slides and remove wax with xylol. 



8. Pass through absolute, 90% and 70% alcohol. 



9. Stain for half an hour in carbol fuchsin (Solution B). 



10. Rinse in distilled water. 



11. Partially differentiate with the acid alcohol (Solution C, 

 above). 



12. Rinse well with distilled water. 



13. Stain for one to two minutes with Ehrlich haematoxylin 

 solution. 



14. Differentiate in the acid alcohol (Solution C). 



15. Rinse well with distilled water. 



16. Immerse in the ammonia solution (Solution E above) for a 

 few seconds. 



17. Rinse well with distilled water. 



18. Stain with the Orange G solution for two to three minutes. 



19. Dehydrate rapidly with two changes of acetone. 



20. Clear in xylol and mount. 



Results: 



Leprosy organisms and neurokeratin are stained red, while 

 nuclei are blue and cytoplasm is yellow. 



84 



