STAINING, PRACTICAL AND THEORETICAL 



4. Wash for several hours in running water. 



5. Pass through ascending grades of alcohol. 



6. Clear in the usual manner and embed in paraffin wax. 



7. Sections not more than 2 to 4^ in thickness are fixed to 

 slides. 



8. Dewax with xylol. 



9. Rinse thoroughly with absolute alcohol and pass through the 

 usual descending grades of alcohol down to distilled water. 



10. Stain for an hour at 60° C. with the acid fuchsin solution. 



11. Allow the preparation to cool to room temperature; then 

 wash with water. 



12. Immerse in Solution C (picric acid) from one second to two 

 minutes, 



13. Rinse in two changes of water. 



14. Stain from one half to one hour in the Light Green 

 solution. 



15. Rinse quickly in absolute alcohol. 



16. Rinse in xylol. 



17. Mount in Canada balsam or Cristalite or D.P.X. 



Results: 



Migrating astrocytes, of varying shades of green and sometimes 

 containing fuchsinophile granules of brown stained lipoid inclu- 

 sions. Lipoid contents of perivascular phagocytes are brown to 

 black. Neuroglia fibres and erythrocytes: red. Medullary sheaths 

 are unstained. Connective tissue: deep green. Nerve cells are 

 pale green with red stippling, while nerve-cell nuclei are a darker 

 green with bright red nuclei. 



Notes: 



(a) The material must be fresh and only small pieces should be 

 employed. 



(b) Sections stained by this technique should appear lilac in 

 colour to the naked eye. 



(c) It is advantageous to experiment in order to determine the 

 optimum staining time in the picric acid and the light green, as 

 results vary according to the material to be stained. 



Reference: Mallory, F. B. (1938). 



264 



