114839-95-1 2,7-Naphthalenedisulfonic acid, 4-((2,4-dihydroxy(hydroxymethyl)-5-((4-((4-nitro-2-sulfophenyl)amino)phenyl)azo)phenyl)azo)-5-hydroxy-, sodium salt 2,7-Naphthalenedisulfonic acid, 4-((2,4-dihydroxy(hydroxymethyl)phenyl)azo)-5-hydroxy-, coupled with diazotized 2-((4-aminophenyl)amino)-5-nitrobenzenesulfonic acid, sodium salts