2107273-12-9

N-(m-PEG4)-N'-(hydroxy-PEG2)-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.