Used as a biological stain in cell viability assays, particularly in the detection of dehydrogenase enzyme activity in living cells. It serves as an alternative to MTT in tetrazolium-based assays, offering improved solubility and reduced cytotoxicity. When metabolically active cells reduce the compound, it forms a red-colored formazan product that can be quantified spectrophotometrically, allowing for the assessment of cell proliferation, cytotoxicity, or metabolic activity. Its lipophilic properties enhance cell membrane penetration, making it effective in both suspension and adherent cell cultures. Commonly applied in pharmacological and toxicological research to evaluate drug effects on cell health.