Eosin Y, a red xanthene dye, has been noted to reduce the affinity of Mg2+-ATPase for ATP and increase the enzyme affinity for Mg2+ at concentrations of 10-50 μM. At higher concentrations near 100 μM the affinity for Mg2+-ATPase for the ion-activator has been shown to be reduced. This compound has also been reported to be a photosensitizer that works as a molecular photoelectrode via catalyzation of the visible-light-driven electron-transfer reaction. Eosin Y has been used to stain structures such as muscle, cytoplasm, and collagen. This agent also enhances fluorescent quenching abilities by forming a complex with polyvinulpyrrolidone. Eosin Y, a red xanthene dye, has been noted to reduce the affinity of Mg2+-ATPase for ATP and increase the enzyme affinity for Mg2+ at concentrations of 10-50 μM. At higher concentrations near 100 μM the affinity for Mg2+-ATPase for the ion-activator has been shown to be reduced. This compound has also been reported to be a photosensitizer that works as a molecular photoelectrode via catalyzation of the visible-light-driven electron-transfer reaction. Eosin Y has been used to stain structures such as muscle, cytoplasm, and collagen. This agent also enhances fluorescent quenching abilities by forming a complex with polyvinulpyrrolidone.