STAINING, PRACTICAL AND THEORETICAL 



5. Immerse slides directly into solution B for one to one and a 

 half hours at 50 to 60° C. in an oven. 



6. Rinse quickly in two changes of distilled water. 



7. Reduce by immersing in solution C for three minutes at 

 25 to 30° C, agitating the slides gently for the first two minutes. 



8. Wash thoroughly in four or five changes of distilled water. 



9. Wash with 50% followed by 70% and 80% alcohols. 



10. Examine under the microscope while the preparation is still 

 wet and if it is found that the staining is^not complete, repeat step 

 5 using the original urea-silver nitrate solution and reduce the 

 time to ten to fifteen minutes; then repeat steps 6, 7, 8 and 9. 



11. Rinse with 95% alcohol. 



12. Dehydrate with two changes of absolute alcohol. 



13. Clear in xylol and mount. 



Results: 



Nerve fibres are stained from brown to black, while nerve end- 

 ings are usually black, and nerve cells from yellow to brown. The 

 background is usually yellow, but its appearance depends upon 

 the kind of tissue and the fixative employed. 



Reference: Ungewitter, L. H. (195 1). 



VERHOEFF'S STAIN 

 For elastic fibres, nuclei and collagen 



Solutiofis required: 



A. Haematoxylin 5% in absolute 



alcohol 20 ml. 



Ferric chloride (hydrated) 10% 



aqueous . . . . . . 8 ml. 



Iodine solution (i gm. iodine, 2 



gm. KI, 50 ml. water) . . 8 ml. 



Note: Solution A deteriorates after twenty-four 

 hours. 



B. Ferric chloride hydrated 2% aqueous. 



C. Van Gieson stain (picro fuchsin). 



458 



