The molecule is an organic sodium salt that is the disodium salt of 4-[(2,4-dimethylphenyl)diazenyl]-3-hydroxynaphthalene-2,7-disulfonic acid. Its use is largely confined to Masson's trichrome, where it gives a slight orange shading to the red of the cytoplasmic structures. It has a role as a histological dye, a cardiotoxic agent and a carcinogenic agent. It contains a 4-[(2,4-dimethylphenyl)diazenyl]-3-hydroxynaphthalene-2,7-disulfonate.
disodium;4-[(2,4-dimethylphenyl)diazenyl]-3-hydroxynaphthalene-2,7-disulfonate