m-PEG4-Propargyl contains a propargyl group. The propargyl group readily reacts with azide-bearing biomolecules via copper catalyzed azide-alkyne Click Chemistry to form a stable triazole linkage. The hydrophilic mPEG tail greatly increase aqueous solubility of the conjugates.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.