SECTION TWO 



Results: 



The presence of tryptophane or other substances containing 

 the indole group is indicated by a bluish or reddish violet colora- 

 tion. 



Notes : 



(a) The method cannot be regarded as specific for tryptophane 

 without confirmation with other methods, and the colour produced 

 by this reaction is insufficiently intense to demonstrate accurate 

 localization. 



(b) It is advisable to protect the sections, with o*5% celloidin 

 solution (as page 509, steps 10-15), before processing. 



References : 



Ehrlich, P. (1901). 

 Lison, L. (1936). 



JANUS GREEN, B - NEUTRAL RED 

 For supravital staining of blood 



Solutions required: 



A. Janus green, B vital stain 0-4% in neutral 

 absolute alcohol. 



B. Neutral red chloride, vital stain 0-25% in 

 neutral absolute alcohol. 



C. Solution A . . . . . . . . 0-07 ml. 



Solution B . . . . . . . . 1 75 ml. 



Absolute alcohol, neutral . . . . 10 ml. 



Note: Solutions A and B are stable, but solution C deteriorates 

 after a few hours, and it should, therefore, be prepared as and 

 when required, for immediate use. 



Technique: 



1. Scrupulously clean, dry slides are flooded with solution C. 



2. Drain and leave to dry. 



3. Place a small drop of blood on each slide. 



4. Cover the blood with scrupulously clean, dry coverslips and 

 allow the blood to spread. 



249 



