The molecule is an organic potassium salt having 2,4,5,7-tetrabromo-9-{2-[(ethyloxy)carbonyl]phenyl}-3-oxo-3H-xanthen-6-olate as the counterion. It has a role as a fluorochrome, a histological dye and a photosensitizing agent. It contains an ethyl eosin anion.
potassium;2,4,5,7-tetrabromo-9-(2-ethoxycarbonylphenyl)-6-oxoxanthen-3-olate