Used primarily in biochemical and molecular biology research as a fluorescent probe or stain for detecting and quantifying nucleic acids, particularly DNA. It binds selectively to double-stranded DNA through minor groove binding, producing strong fluorescence enhancement upon binding. This property makes it valuable in assays such as gel staining, cell cycle analysis, and apoptosis detection in flow cytometry. Also employed in studies involving live and fixed cells due to its cell membrane permeability and low cytotoxicity at working concentrations. Its high affinity for AT-rich regions of DNA allows for specific targeting in chromosomal staining and DNA footprinting experiments.