5-amino-3-[[4'-[(6-amino-1-hydroxy-3-sulpho-2-naphthyl)azo][1,1'-biphenyl]-4-yl]azo]-4-hydroxynaphthalene-2,7-disulphonic acid, sodium salt

5-Amino-3-[[4'-[(6-amino-1-hydroxy-3-sulfo-2-naphthalenyl)azo][1,1'-biphenyl]-4-yl]azo]-4-hydroxy-2,7-naphthalenedisulfonic acid/sodium,(1:x) salt