Synonyms: 2,7-Naphthalenedisulfonic acid, 4-amino-5-hydroxy-, coupled with diazotized 2'-(4-aminophenyl)-6-methyl(2,6'-bibenzothiazole)-7-sulfonic acid, diazotized 3,3'-dimethoxy(1,1'-biphenyl)-4,4'-diamine and 5,5'-(oxybis((5-hydroxy-3,1-phenylene)oxy))bis(1,3-benzenediol), sodium salts