YO-PRO-3 (YO-PRO 3) serves as a versatile dye employed across various domains, including biological research and clinical diagnostics. It enables scientists to examine cell structures, trace biomolecules, assess cellular functions, identify different cell types, and investigate tissue pathology, as well as monitor microorganisms. Beyond biomedical applications, this dye is utilized in the dyeing of textiles, the development of functional textiles, food coloring, and in the manufacture of dye-sensitized solar cells, highlighting its extensive use in both traditional and emerging industries.