Widely used in cell biology and microbiology for DNA staining, particularly in fluorescence microscopy and flow cytometry. It binds selectively to the minor groove of double-stranded DNA, especially AT-rich regions, emitting strong blue fluorescence when excited by UV light. Commonly used to stain live and fixed cells due to its cell membrane permeability. Frequently applied in nuclear visualization, cell cycle analysis, and apoptosis studies. Also used in chromosome counting and as a counterstain in multicolor fluorescent labeling experiments. Its high sensitivity allows detection of small amounts of DNA, making it suitable for detecting microbial contamination or analyzing sperm cells.