METHOD VII. 



THE INTRA VITAM METHYLEN-BLUE METHOD. 



Applications of methylen-blue to the fresh tissue for the 

 external morphology of the neurone and to demonstrate the 

 course and termination of the axone. Especially suited for the 

 architecture of peripheral ganglia and muscle nerve termina- 

 tions, but may be applied to the central nervous system." 



SPECIAL REAGENTS REQUIRED. 



A. Physiological (normal) salt solution. — 



Sodium chloride, 3 g. 

 Distilled water, 400 cc. 



B. The stain (i per cent, methylen-blue). — 



Methylen-blue {rectificiert nach Ehrlich, Griibler), 2 g. 



Physiological salt solution (A), 200 cc. 

 Warm the mixture till it steams, shake well, let cool, and filter. 

 Several brands of methylen-blue have been suggested by different authors. 

 The above, however, is that most generally recommended. 



C. Fixing fluids. — 



1. Saturated aqueous solution of ammonium picrate. — 



Ammonium picrate (pure), 2 g. 

 Distilled water, 200 cc. 

 Let undissolved picrate settle, and decant the fluid when needed. 



2. Bethe's fixing fluid. — 



Ammonium molybdate, 2 g. 

 Distilled water, 40 cc. 

 Hydrochloric acid (C. P. cone), 2 drops. 

 Place on ice before using. 



D. Preserving and mounting medium. — 



Saturated ammonium picrate (C, i), 50 cc. 

 Pure glycerine (acid-free), 50 cc. 



" The following applications of methylen-blue are based upon methods pursued 

 by Ehrlich, Bethe, Dogiel, and Huber. 



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