has part has role independent continuant naphthalenesulfonic acid organic sodium salt carcinogenic agent fluorochrome organosulfonate salt histological dye trypan blue An organosulfonate salt that is the tetrasodium salt of 3,3'-[(3,3'-dimethylbiphenyl-4,4'-diyl)didiazene-2,1-diyl]bis(5-amino-4-hydroxynaphthalene-2,7-disulfonic acid). CHEBI:78897 trypan blue(4-)