Bis-PEG4-acid is a PEG derivative containing two terminal carboxylic acid groups. The terminal carboxylic acids canreact with primary and secondary amine groups in the presence of coupling reagents such as EDC, DCC and HATU to form a stable amide bond. When used sequentially, two different amine bearing biomolecules can be conjugated in a controlled maner. The hydrophilic PEG spacer can increase the aqueous solubility of the resulting conjugates.
Axispharm offers 3000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.