4arm-PEG-SS (4arm-Succinimidyl Succinate-PEG), MW 40K is a multi-arm PEG derivative with a C2 hydrocarbon ester linkage between the PEG and the NHS ester.The number of ethylene oxide units in the PEG chain may not be equal for all arms.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.