1,6-Naphthalenedisulfonic acid, 7-[[4'-[(8-amino-1-hydroxy-5-sulfo-2-naphthalenyl)azo]-3,3'-dimethyl[1,1'-biphenyl]-4-yl]azo]-8-hydroxy-, trisodium salt 1,6-Naphthalenedisulfonic acid, 7-[[4'-[(8-amino-1-hydroxy-5-sulfo-2-naphthyl)azo]-3,3'-dimethyl-4-biphenylyl]azo]-8-hydroxy-, trisodium salt 6420-13-9 C.I. 23740 Columbia Blue G NSC75780 Pontamine Blue CLG