MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



scopic examination, observing the nuclei rather than the non- 

 nuclear material, as it may not be possible to remove all the blue 

 stain from the latter without completely decolorizing the nuclei. 



Note: If 50% alcohol is found inadequate, then solutions 

 E, F, and G should be tried in turn to ascertain which is the most 

 satisfactory for the particular plant material. Some material, 

 e.g. sweet clover epidermis needs little or no differentiation. 

 Solutions F and G are more active as differentiators than E or 

 50% alcohol. 



4. Place in 95% alcohol for two minutes. 



5. Counterstain epidermis if desired with solution H for one 

 minute but this may not be advantageous in the case of smears. 



6. Rinse in 95% alcohol. 



7. Immerse in two changes of Isopropyl alcohol for two minutes 

 in each. 



8. Immerse in a third change of Isopropyl alcohol for five 

 minutes. 



9. Clear in xylol and mount in Clearmount or balsam. 



Results: 



Nuclei, bright blue. If counterstain is used, the background is 

 bright red. 



Reference: Hoffmesster, E. R. (1953), Stain Tech., 28, no. 6, 309. 



286 



