N-(azide-PEG3)-N'-(Amine-C3-Amide-PEG4)-Cy5

N-(azide-PEG3)-N'-(Amine-C3-PEG4)-Cy5 is a PEG linker containing a cyanine dye with excitation/emmission maximum 649/667 nm as well as an azide group, which enables Click Chemistry. The hydophilic PEG spacer increases solubility in aqueous media.