The molecule is a naphthalenesulfonic acid that is the free acid form of the dye Sirius red F3B. The hexasodium salt is a histological dye used principally in staining methods for collagen and amyloid. It has a role as a fluorochrome and a histological dye. It is a member of ureas, a member of naphthols, a naphthalenesulfonic acid and a member of azobenzenes. It is a conjugate acid of a Sirius red F3B(6-).
4-hydroxy-7-[[5-hydroxy-7-sulfo-6-[[2-sulfo-4-[(4-sulfophenyl)diazenyl]phenyl]diazenyl]naphthalen-2-yl]carbamoylamino]-3-[[2-sulfo-4-[(4-sulfophenyl)diazenyl]phenyl]diazenyl]naphthalene-2-sulfonic acid