Cy3Dextran (MW 100000) is a fluorescent labeling reagent combining Cy3 fluorescent dye and Dextran. The Cy3 fluorophore is commonly employed in applications such as immunolabeling, nucleic acid labeling, fluorescence microscopy, and flow cytometry. Dextran is known to inhibit platelet aggregation and coagulation factors and is used as a plasma volume expander (Ex/Em = 550/570 nm).