Used as a redox indicator in biochemical and histochemical assays for detecting dehydrogenase activity and cellular metabolic function. It is reduced by NADH-dependent enzymes or other biological reductants to form an insoluble purple formazan precipitate, enabling colorimetric or microscopic visualization. Commonly applied in research laboratories for cell viability assays, enzyme kinetics studies, and antioxidant capacity evaluation in biological samples such as cells, tissues, and fluids. Also utilized in diagnostic kits for assessing metabolic disorders and microbial activity. Its sensitivity to redox reactions makes it a valuable tool in academic, pharmaceutical, and clinical settings.