2-Naphthalenesulfonic acid, 7,7'-iminobis(3-((4-((4-amino-2-sulfophenyl)azo)-7-sulfo-1-naphthalenyl)azo)-4-hydroxy-, hexasodium salt 2-Naphthalenesulfonic acid, 7,7'-iminobis(3-((4-((4-amino-2-sulfophenyl)azo)-7-sulfo-1-naphthyl)azo)-4-hydroxy-, hexasodium salt 7,7'-Iminobis(3-((4-((4-amino-2-sulfophenyl)azo)-7-sulfo-1-naphthyl)azo)-4-hydroxy-2-naphthalenesulfonic acid), tetrasodium salt 71033-18-6