2,7-Naphthalenedisulfonic acid, 4,4'-[(3-sulfo-4,4'-biphenylylene)bis(azo)]bis[3-amino-, pentasodium salt 2,7-Naphthalenedisulfonic acid, 4,4'-[(3-sulfo[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[3-amino-, pentasodium salt 574-64-1 C.I. 22850 NSC11243 Trypan Red