MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



cellular material. The picric acid gives a light yellowish back- 

 ground. 



Often the stain reveals the presence of lightly stained mucus-like 

 envelope, apparently covering the cast material. This material is 

 often clearly seen at the end of a cast which has apparently been 

 squarely broken off. 



PINACYANOL - NEUTRAL RED 



For supra-vital staining of blood 



Note: Pinacyanol is superior to janus green in that it does not 

 fade : it is very selective for mitochondria, and it does not inhibit 

 the effect of neutral red. It has the disadvantage, however, of 

 being extremely costly. 



Solutions required: 

 Stock solutions: 



A. Pinacyanol o-i% in absolute alcohol. 



B. Neutral Red o-i% in absolute alcohol. 



Staining solutions: 



C. for mitochondria only 



Solution A . . . . . . . . I ml. 



Absolute alcohol . . . . . . 20 ml. 



D. for mitochondria^ nuclei and other cell granules 

 Solution A . . . . . . . . I ml. 



Solution B . . . . . . . . 2 ml. 



Absolute alcohol . . . . . . 20 ml. 



Notes: 



(a) Solutions C and D deteriorate after a few hours and should, 

 therefore, be prepared only as and when they are required for 

 immediate use. 



(b) The proportions and dye concentrations of either of these 

 two solutions may be varied to suit particular specimens. 



Technique: 



I. Scrupulously clean dry slides are flooded with solution C 

 or D, whichever is required. 



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