Used as a colorimetric indicator in analytical chemistry for titrations involving redox reactions. Commonly employed in educational and research laboratories to demonstrate dye behavior under varying pH and oxidation states. Serves as a visual tracer in environmental studies to track fluid flow and mixing in water systems. Also utilized in biological staining to enhance contrast in microscopy, particularly for observing cell structures and membrane permeability. Its consistent concentration in standard solution form ensures reliable and reproducible results in qualitative and quantitative analysis.