D&C Red No. 28
Phloxine B is an organic sodium salt that is the disodium salt of 2,3,4,5-tetrachloro-6-(2,4,5,7-tetrabromo-6-hydroxy-3-oxo-3H-xanthen-9-yl)benzoic acid. It is used in the hematoxylin phloxine saffron (HPS) stain, stains paneth cell granules in Lendrum's phloxine-tartrazine method, and can be used to demonstrate alcoholic hyaline. It has a role as a histological dye and a fluorochrome. It contains a 2',4',5',7'-tetrabromo-2,3,4,5-tetrachlorofluorescein(2-).