DBCO-NHCO-PEG13-NHS ester bears NHS ester that reacts with primary and secondary amines such as the side chain of lysine residues or amino modified surfaces an amide bond. DBCO on the other hand readily react with azide bearing biomolecule through a copper-free click reaction instantly and in high yield. The hydrophilic PEG spacer arm improves water solubility.
Axispharm offers 3000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.