Synonyms: Cuprate(4-),[m-[[3,3'-[(3,3'-dihydroxy[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[5-amino-4-hydroxy-2,7-naphthalenedisulfonato]](8-)]]di-,tetraammonium; Cuprate(4-), [m-[[3,3'-[[3,3'-di(hydroxy-kO)[1,1'-biphenyl]-4,4'-diyl]bis(azo-kN1)]bis[5-amino-4-(hydroxy-kO)-2,7-naphthalenedisulfonato]](8-)]]di-,tetraammonium (9CI); 2,7-Naphthalenedisulfonic acid,3,3'-[(3,3'-dihydroxy[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[5-amino-4-hydroxy-,copper complex