Used as a fluorescent probe in biological imaging, particularly for tracking lipid metabolism and membrane dynamics in live cells. Its structure allows integration into lipid bilayers, where it emits strong fluorescence upon excitation, enabling real-time visualization of cellular processes such as endocytosis, lipid trafficking, and apoptosis. The ammonium salt form enhances solubility in aqueous buffers, making it suitable for cell-based assays. Commonly applied in fluorescence microscopy and flow cytometry due to its photostability and high quantum yield. Also utilized in studies involving liposome formation and drug delivery systems to monitor fusion and release events.