4-Amino-5-hydroxy-6-[[4-[[4-[[2-hydroxy-4-[(2-methylphenyl)amino]phenyl]azo]phenyl]amino]-3-sulfophenyl]azo]-2,7-naphthalenedisulfonic acid/sodium,(1:x) salt

4-amino-5-hydroxy-6-[[4-[[4-[[2-hydroxy-4-[(o-tolyl)amino]phenyl]azo]phenyl]amino]-3-sulphophenyl]azo]-3-[(4-nitrophenyl)azo]naphthalene-2,7-disulphonic acid, sodium salt