DEAE-dex-Cy5 is a fluorescent labeling reagent that combines the Cy5 fluorescent dye with Dextran (dex) and diethylaminoethyl (DEAE). Cy5, a cyanine dye, has a wavelength of approximately 662 nm and is used for molecular labeling and microscopic imaging. Dextran inhibits platelet aggregation and coagulation factors, serving as a plasma volume expander.