has part has role has functional parent xanthene dye fluorescin organic potassium salt fluorochrome rose bengal An organic potassium salt that is the dipotassium salt of 2,3,4,5-tetrachloro-6-(2,4,5,7-tetraiodo-6-hydroxy-3-oxoxanthen-9-yl)benzoic acid. CHEBI:52261 rose bengal(2-) histological dye