DOX-PEG-Cy3 (Doxorubicin-PEG-Cy3) is a Cy3 labeled DOX-PEG conjugate. The Cy3 fluorophore is commonly used in applications such as immunolabeling, nucleic acid labeling, fluorescence microscopy, and flow cytometry. Cy3 has an emission maximum around 562-570 nm. DOX is a broad-spectrum anthracycline antibiotic with cytotoxic properties.