Widely used in fluorescence microscopy to stain DNA in cells. It binds strongly to the minor groove of double-stranded DNA, emitting bright blue fluorescence when excited by UV light. Commonly applied in cell cycle analysis, nuclear morphology studies, and apoptosis detection. Frequently used in combination with other fluorescent markers for multicolor imaging. Suitable for both fixed and live cell staining, though it is more commonly used in fixed cells due to limited cell membrane permeability. Also employed in microbiology to detect microbial cells in environmental samples and in tissue sections for histological analysis.