Synonyms: Cuprate(4-), (mu-(4,4'-bis((6-((3-carboxyphenyl)amino)-1-(hydroxy-kappaO)-3-sulfo-2-naphthalenyl)azo-kappaN1)(1,1'-biphenyl)-3,3'-di(carboxylato-kappaO)(8-)))di-, tetrasodium;Cuprate(4-), (mu-(4,4'-bis(2-(6-((3-carboxyphenyl)amino)-1-(hydroxy-kappaO)-3-sulfo-2-naphthalenyl)diazenyl-kappaN1)(1,1'-biphenyl)-3,3'-di(carboxylato-kappaO)(8-)))di-, sodium (1:4);Tetrasodium (mu-(4,4'-bis((6-(3-carboxyanilino)-1-hydroxy-3-sulpho-2-naphthyl)azo)(1,1'-biphenyl)-3,3'-dicarboxylato(8-)))dicuprate(4-)