4arm-PEG-SAS

4arm-PEG-SAS (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. SAS has a longer hydrolytic half-life and is therefore more stable in aqueous buffers than many other types of NHS esters. Four-arm polyethylene glycol derivatives have a variety of active groups, and can modify proteins, peptides and other materials through their functional groups. Therefore, it is widely used in the modification of polyethylene glycol (PEG) in various biological nanomaterials.