mPEG-succinimidyl propionate (mPEG-SPA), MW 5K is an amine-reactive NHS PEG product that reacts with primary amine groups under basic conditions. Similar to mPEG-SC, mPEG-SPA also has high activity and good stability in aqueous solution.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.