4arm-PEG-SAS, MW 20K (4arm-PEG-Succinimidyl Amido Succinate) is an amine-reactive multi-arm PEG polymer. There are succinimidyl NHS ester groups at each end of the four arms attached to a pentaerythritol core. There is a C2 hydrocarbon amide bond between the PEG and the NHS ester. Four-arm polyethylene glycol derivatives have a variety of active groups, and can modify proteins, peptides and other materials through their functional groups.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.