2,7-Naphthalenedisulfonic acid, 4-amino-3,6-bis((4-((2,4-diamino-5-sulfophenyl)azo)phenyl)azo)-5-hydroxy-, tetrasodium salt 4-Amino-3,6-bis((4-((2,4-diamino-5-sulfophenyl)azo)phenyl)azo)-5-hydroxy-2,7-naphthalenedisulfonic acid tetrasodium salt 72927-74-3