1,1'-Dioctadecyl-3,3,3',3'-tetramethyl indotricarbocyanine iodide

DiIC18(7) [DiR] is a lipophilic, near-infrared fluorescent cyanine dye. The dye is useful for labeling cytoplasmic membranes and has been widely used for near-infrared in vivo imaging and for in vitro studies. The two long 18-carbon chains insert into the cell membrane, resulting in specific and stable cell staining with no or minimal dye transfer between cells. DiR diffuses laterally to stain the entire cell, allowing it to be used as an anterograde and retrograde tracer of neurons. In intact tissue, the dye does not transfer from labeled to unlabeled cells, but some transfer may occur when the membrane is disrupted, for example, after sectioning. Cell staining can be effected using the dye at 1-10 uM concentration and 10-20 min incubation time. The dye can be used for labeling nanoparticles and extracellular vescicles. The dye is weakly fluorescent until incorporated into membranes. Spectral Data: Excitation max: ~ 748nm, Emission max: ~780nm (MeOH).