The molecule is a naphthalenesulfonic acid that is the free acid form of the dye Sirius red F3B (the trisodium salt). It has a role as a fluorochrome and a histological dye. It is a member of naphthols, a member of azobenzenes, a bis(azo) compound, an aminonaphthalenesulfonic acid, a secondary amino compound and an aromatic ether. It is a conjugate acid of a Durazol blue 4R(3-).
4-[[4-[(6-anilino-1-hydroxy-3-sulfonaphthalen-2-yl)diazenyl]-5-methoxy-2-methylphenyl]diazenyl]-5-hydroxynaphthalene-2,7-disulfonic acid