ChEBI: Trypan blue is 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). It has a role as a histological dye, a fluorochrome and a carcinogenic agent. It is an organosulfonate salt and an organic sodium salt. It contains a trypan blue(4-).NCI Thesaurus (NCIt): Trypan Blue is an acid azo dye commonly used as a stain to distinguish viable from non-viable cells. It turns dead cells blue and viable cells unstained. It is a known animal carcinogen and an experimental teratogen.