2,7-Naphthalenedisulfonic acid, 4-amino-3,6-bis((4-amino-2-sulfophenyl)azo)-5-hydroxy- 4-Amino-3,6-bis((4-amino-2-sulfophenyl)azo)-5-hydroxy-2,7-naphthalenedisulfonic acid 4-Amino-3,6-bis((4-amino-2-sulphophenyl)azo)-5-hydroxynaphthalene-2,7-disulphonic acid 66620-37-9 EINECS 266-428-7