Widely used as a near-infrared fluorescent dye in biological imaging and labeling applications. Its strong absorption and emission in the NIR region allow deep tissue penetration with minimal autofluorescence and low background interference, making it ideal for in vivo imaging. Commonly employed in fluorescence microscopy, flow cytometry, and molecular probes for tracking cellular processes. Due to its lipophilic nature, it readily incorporates into cell membranes and can be used to study membrane dynamics and lipid rafts. Also utilized in photodynamic therapy research and as a component in optical sensors for detecting biomolecules.