Cy3Dextran (MW 5000) is a fluorescent labeling reagent that combines the Cy3 fluorescent dye with Dextran. The Cy3 fluorophore is commonly used in applications such as immunolabeling, nucleic acid labeling, fluorescence microscopy, and flow cytometry. Dextran acts as a plasma volume expander and inhibits platelet aggregation and coagulation factors (Ex/Em = 550/570 nm).