This dye has also been used for vital staining; and has been 

 employed by Zschokke as a plasma stain especially in contrast to 

 haematoxylin. 



TRYPAN BLUE C. I. NO. 477 



Synonyms: Chlorazol blue SB. Benzo blue 3B. Dianil blue H3G. 



Congo blue 3B. Naphthamine blue 3BX. Benzamine 



blue SB. Azidine blue SB. Niagara blue SB. 



HaN OH HO NHa 



\ I N = N_/~V_/-"\_N = N I / 



CH3 CHj /\/\/\ 



NaSOi SOiNa NaSO^ SOjNa 



{An acid dye.) 



Apparently the only biological use of this dye is in vital staining. 



Other azo dyes sometimes mentioned in connection with hist- 

 ology are: 



Janus red; C. I. No. <im 



Tropaeolin O; C. I. No. 148. Syn: Chrysoin. Gold yellow. Acid 

 yellow 



Tropaeolin Y; C. I. No. 148 (see note). 



Roccellin; C. I. No. 176. Syn: Fast red A, AV, or 0. Cerasin, 

 Rubidin. Cardinal red. 



Crystal ponceau 6R; C. I. No. 89; Syn: Ponceau 6R. 



Carmin naphtha; C. I. No. 24. Syn: Sudan 8. Scharlach B. 

 Oil yellow. 



Alizarin yellow GG; C.I. No. 36. Syn : Anthracene yellow. Ben- 

 zene yellow. 



Chrysoidin R; C. I. No. 21. Syn : Cotton orange. Cerotin orange. 



Chrysoidin Y; C. I. No, 20. Syn: Brown salt R. Dark brown 

 salt R. 



Alizarin yellow R; C. I. No. 40. Alizarin orange. Benzene yel- 

 low PN. Orange R; Anthracene yelloiv RN. 



Diamond flavine; C. I. No. 110. 



Diamond black F; C. I. No. 299. Syn.: Salicin black. Chrome 

 black. 



Niagara blue 4B; C. I. No. 520. Syn. : Niagara sky blue. Benzoin 

 sky blue. Dianil blue H 6 G. Congo sky blue. Naphthamine blue. 



41 



