Eosin 5-isothiocyanate is a versatile dye employed in a variety of biological experiments. Dyes like this one are essential for observing and analyzing cell structures, tracking biomolecules, assessing cell functions, distinguishing cell types, detecting biomolecules, studying tissue pathology, and monitoring microorganisms. Their applications span basic scientific research to diverse clinical diagnostics. Additionally, dyes are extensively used in traditional fields like textile dyeing, as well as in new areas such as functional textile processing, food pigments, and dye-sensitized solar cells.