4,4'-[(2,2'-disulpho[1,1'-biphenyl]-4,4'-diyl)bis[azo(4,6-dihydroxy-m-phenylene)azo]]bis[5-hydroxy-6-[(4-nitrophenyl)azo]naphthalene-2,7-disulphonic] acid, sodium salt
CAS No. 93804-98-9