Features and Benefits

Acid-dPEG^®₉-NHS ester is a unique heterobifunctional dPEG^® crosslinking product which allows conjugation to two different moieties, each containing free amines. Because the single molecular weight dPEG^® spacers contain an N-hydroxysuccinimide ester only on one end of the spacer, greater control of the conjugation reaction can be maintained. The free acid end of the spacer can be left unreacted to modify the surface properties of the molecule to which it is conjugated, or the free acid end can be activated and conjugated to a different group at a later time. The dPEG^® spacers provide precise spacing/distance control, and the dPEG^® itself provides the well-known benefits of increased water solubility; decreased immunogenicity; protection from proteolysis; increased hydrodynamic volume; and increased serum half-life.