The aldehyde group readily reacts with primary amines, aminooxy and hydrazide to form a reversible oxime or hydrazone linkage. After de-Boc, the free amine can under conjugation process with acid or activated acid ester bearing biomolecules. The PEG spacer increase the solubility of the resulting complex in aqueous media.
AxisPharm offers 4000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.