234 Specific Examples of Slide Making 



muscle. If a small quantity of red is picked up by the muscle fibers, 

 it will be removed in the process of differentiation. The time is not critical, 

 but that given in the formula cited (2 to 10 min) will be found to cover 

 the range normally necessary. 



A slight difficulty will be occasioned in dehydration through the tend- 

 ency of the picric acid to leave the tissues in the various alcohols em- 

 ployed. Either this may be prevented by dehydrating in a series of 1 per 

 cent solutions of picric acid in the various alcohols, or it may be ignored 

 completely according to the depth of yellow color that is to be retained. 

 If, on the contrary, a very pale yellow is desired, the sections may have to 

 be put in 96 per cent alcohol, for a period of time beyond that necessary 

 for dehydration, to remove the unwanted picric acid. Then the sections 

 are cleared in xylene in the normal manner and mounted in balsam. 



SUMMARY 



1. Place a 5-mm slice of tongue in 100 ml of Petrunkewitsch's fluid for 

 1 to 2 days. 



2. Wash overnight in running water. Dehydrate, clear, embed in low- 

 melting-point wax, and cut 10- to 12-/x sections. 



3. Flatten sections and squeeze to slide. Dry as rapidly as possible. 

 Dewax dried sections and grade down to water through usual reagents. 



4. Stain in celestine blue B for 1 min. Overstating is not possible. 



5. Rinse in water and stain in van Gieson's picro acid fuchsin from 2 

 to 10 min. 



6. Dehydrate and differentiate in 95% alcohol. Clear and mount in the 

 usual way. 



