Used as a redox-sensitive dye in biochemical assays to measure cell viability and cytotoxicity. It is particularly effective in colorimetric assays for quantifying metabolic activity in living cells, as it is reduced by mitochondrial dehydrogenases to form a colored formazan product. Widely applied in drug screening and toxicology studies to assess the effects of compounds on cell health. Also employed in microbiology for evaluating bacterial growth and metabolic activity. Its water solubility and sensitivity make it suitable for high-throughput screening methods.