trisodium 4-[[2,4-dihydroxy-3-[[4-(6-methyl-7-sulphonato[2,6'-bibenzothiazol]-2'-yl)phenyl]azo]phenyl]azo]-5-hydroxynaphthalene-2,7-disulphonate

4-[[2,4-Dihydroxy-3-[[4-(6-methyl-7-sodiosulfo[2,6'-bibenzothiazol]-2'-yl)phenyl]azo]phenyl]azo]-5-hydroxy-2,7-naphthalenedisulfonic acid disodium salt