Pyranine (hydrate) (HPTS (hydrate); Solvent Green 7 (hydrate)) is a versatile dye. In biological experiments, dyes are essential tools for observing and analyzing cell structures, tracking biomolecules, assessing cellular functions, distinguishing cell types, detecting biomolecules, studying tissue pathology, and monitoring microorganisms, with applications spanning from fundamental scientific research to clinical diagnostics. Additionally, dyes are widely used in traditional areas like textile dyeing and emerging fields such as functional textile processing, food coloring, and dye-sensitized solar cells.