S6 



Biological Stains 



Brilliant croceine has been mentioned by Lillie (1945c) as a sub- 

 stitute for "xylidine ponceau" in the Masson triple stain. 



cr 

 o 



o 

 o 



L I I I I I I I I l^\ I I I I J 

 400 460 520 580 640 700 



WAVELENGTH Tn JH 



Fig. 9. Spectral curves of three azo dyes: 



1. Sudan III. 



2. Sudan IV. 



3. Sudan black B. 



D4 SUDAN III C. I. NO. 148 



Synonyms: Sudan G. Tony red. Scarlet B,fat soluble. Fat 

 ponceau G. Oil red AS, 0, B or SB. Cerasin red. 



/\_N=N_ 



H0_ 



N = N" 



C22H16N4O; Mol. Wt. 352.380 

 {A weakly acid dye; absorption maxima in alcohol 508-510) 

 Solubility at 26°C: in water nil; in alcohol 0.15% 



