Used as a mitochondrial indicator in cell viability assays, particularly in the MTT assay format. It penetrates cell membranes and is reduced by dehydrogenase enzymes in metabolically active cells to form a colored formazan product, which can be quantified spectrophotometrically. This allows researchers to assess cell proliferation, cytotoxicity, and apoptosis in various biological studies, including drug screening and cancer research. Its methoxyphenyl modification enhances solubility and sensitivity in certain cell types, making it suitable for high-throughput screening applications.