tetrasodium 4-amino-5-hydroxy-3-[[4-[[4-[[4-hydroxy-2-[(o-tolyl)amino]phenyl]azo]phenyl]amino]-3-sulphonatophenyl]azo]-6-[(4-sulphonatophenyl)azo]naphthalene-2,7-disulphonate

4-Amino-5-hydroxy-3-[[4-[[4-[[4-hydroxy-2-[(2-methylphenyl)amino]phenyl]azo]phenyl]amino]-3-sulfophenyl]azo]-6-[(4-sulfophenyl)azo]-2,7-naphthalenedisulfonic acid tetrasodium salt