STAINING, PRACTICAL AND THEORETICAL 



7. Continue the differentiation in several changes of 70% 

 alcohol until the grey and white matter can be distinguished, but 

 taking care not to over- differentiate. 



8. Wash in distilled water. 



9. Immerse in the lithium carbonate solution for three to five 

 seconds, but no longer. 



10. Complete the differentiation by immersing in several 

 changes of 70% alcohol, until the white matter is stained greenish- 

 blue in sharp contrast with the colourless grey matter. 



11. Wash thoroughly in distilled water. 



12. Stain for one to two minutes in the cresyl fast violet solution, 

 which should be warmed carefully and filtered before use. 



13. Wash for two or three seconds in distilled water. 



14. Differentiate in several changes of 95% alcohol until colour 

 ceases to come away from the preparation and the alcohol is no 

 longer tinted. 



15. Clear in xylol-terpineol (Solution D). 



16. Clear in xylol and mount. 



(b) Paraffin sections 



1. Cut sections 15 to lOfi in thickness and fix to slides. 



2. Remove paraffin wax with xylol and pass through absolute 

 alcohol. 



3. Rinse with several changes of 95% alcohol. 



4. Stain with the Luxol fast blue solution for five to twenty-four 

 hours, but preferably not less than sixteen hours, at 57° C. in an 

 oven, taking precautions to prevent the loss of alcohol through 

 evaporation from the staining solution. 



5. Proceed exactly as at Stage 4 in the technique given above 

 for frozen sections, except at Stage 12 the cresyl violet should be 

 allowed to act for six minutes. 



(c) Celloidin sections (loose) 



1. Cut sections 15 to 30/x in thickness and place them into 75% 

 alcohol. 



2. Stain from five to twenty-four hours, but preferably not less 

 than sixteen, in the Luxol fast blue solution at 57° C. in an oven, 



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