Cy3-PEG-NH2 (MW 3400) is a polyethylene glycol derivative that includes Cy3 fluorescent dye, polyethylene glycol (PEG), and an amino group. The Cy3 fluorophore is commonly applied in immunolabeling, nucleic acid labeling, fluorescence microscopy, and flow cytometry. It has a peak emission wavelength of approximately 562-570 nm. Cy3-PEG-NH2 (MW 3400) can be utilized for fluorescence imaging, fluorescent tracing, and fluorescent labeling.