Azido-PEG3-S-PEG3-azide contains two terminal carboxylic acid groups. The two carboxylic acid groups can undergo sequential amide coupling with primary/secondary amine groups using EDC, DCC or HATU activators. The PEG spacer provides additional water solubility of the compound.
Axispharm offers 3000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.