234 Biological Stains 



Trade names; Echtrotsalz B (Holborn); Fast red salt B (Gurr); 

 Naphthanil diazo red B (Gurr); Kernechtrotsalz B (Gurr); 

 Nuclear fast red salt B (Gurr); Fast red B salt (Nat. Aniline) 

 See also nuclear fast red salt B in Chap. V (p. 70). 



DIAZO SALT OF 4-NITRO-2-AMINO ANISOLE 



OCH3 



/ 



/— \_N=NC1 



\_/ 

 O2N— 



Trade name: Scarlet RS salt (Nat. Aniline) 



DIAZO SALT OF L-AMINO ANTHRAQUINONE 



O N=NC1 



/\_C_/\ 



O 



Trade names: Naphthanil diazo red AL (DuPont); Fast red salt V 

 (Ciba); Red ALS salt (Nat Aniline). 



The histochemical use of this reagent for demonstrating es- 

 terase, as well as a method for preparing it, as described by Nach- 

 las and Seligman (1949). 



TETRAZO SALT OF O-ANISIDINE 



OCH3 OCH3 



\ / 



C1N=N_/— \_/— \_N=NC1 



Trade names: Naphthanil blue salt B, Fast blue salt B, Fast blue 

 salt BN (Gurr); Diazo blue B (DuPont); Blue BNS salt (Nat. 

 Aniline). 



TETRAZO SALT OF 4,4-DIAMINODIPHENYLAMINE 



C1N=N_/— \_NH_/-~\_N=NC1 



Trade name: Black BS salt. 



DIAZO SALT OF 6-BENZOYLAMINO-4-METHOXY-3-AMINO TOLUENE 



O CH3 



C — NH„/~\_N=:NC1 

 / 



Trade name: Violet BN salt (Nat. Aniline). 



