2,7-Naphthalenedisulfonic acid, 4-amino-3-((4'-((8-amino-1-hydroxy-3,6-disulfo-2-naphthalenyl)azo)-2,2'-disulfo(1,1'-biphenyl)-4-yl)azo)-5-hydroxy-, sodium salt 4-Amino-3-((4'-((8-amino-1-hydroxy-3,6-disulpho-2-naphthyl)azo)-2,2'-disulpho(1,1'-biphenyl)-4-yl)azo)-5-hydroxynaphthalene-2,7-disulphonic acid, sodium salt 83221-64-1 EINECS 280-242-3