endo-BCN-PEG8-NHS ester is a monodisperse PEG linker containing an NHS ester group and a BCN group. It can be used to label the primary amines (-NH2) of proteins, amine-modified oligonucleotides, and other amine-containing molecules. The BCN group can react with azide-tagged biomolecules under copper free condition. The hydrophilic PEG spacer increases solubility in aqueous media. Reagent grade, for research purpose. Please contact us for GMP-grade inquiries.