Used extensively as a fluorescent cell membrane label in biological imaging. It readily incorporates into lipid bilayers and emits strong red fluorescence, making it ideal for tracing cell migration, monitoring membrane dynamics, and visualizing cellular structures in live and fixed cells. Commonly applied in neuroscience for neuronal pathway tracing due to its photostability and long-wavelength emission, which allows deep tissue imaging with minimal autofluorescence. Also employed in flow cytometry and multicolor labeling experiments when paired with other fluorophores. Its lipophilic nature ensures even staining across membranes, providing consistent and reliable imaging results.