N-(m-PEG4)-N'-(4-hydroxycyclohexyl-1-amido-PEG4)-Cy5 is a cyanine labeled PEG linker with excitation/emmission maximum 649/667 nm containing hydroxyl group, which enables further derivatized or replaced with other reactive functional groups. Hydophilic PEG spacer increases solubility in aqueous media and reduces steric hindrance during binding.
