m-PEG-thiol, MW 40K is a polyPEG with thiol groups. The thiol group can react with maleimide or disulfide. Can form metal thiolate complexes with transition metals. Increasing the number of PEG repeating units also improves the water solubility of the compounds.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.