5(6)-Carboxynaphthofluorescein diacetate serves as a fluorescent substrate in esterase assays, where it is cleaved by intracellular esterases, resulting in red fluorescence for enzyme activity measurement (Ex = 590 nm; Em = 645 nm) [1].
TFAX 594,SE is a red fluorescent dye that maintains its fluorescence properties regardless of the pH level, ranging from 4 to 10. This dye produces highly intense and photostable conjugates when combined with proteins or antibodies, such as goat anti-mouse IgG.