The molecule is an organic sodium salt that is 4-aminoazobenzene-3,4'-disulfonic acid in which the protons of both of the sulfo groups have been replaced by sodium ions. It is used as a biological stain. It was formerly used as a food coloring agent (E105), but its use in food or drinks is now forbidden. It has a role as a histological dye. It contains a 4-aminoazobenzene-3,4'-disulfonate.
disodium;2-amino-5-[(4-sulfonatophenyl)diazenyl]benzenesulfonate