Description Features and Benefits Phthalimidooxy-dPEG®12-NHS ester allows introduction of an oxyamine function onto a target molecule for cross-linking proteins or for creating stable conjugates with the target molecule. The oxyamine function is protected by a phthalimido protecting group on one end of the spacer arm, and the spacer is installed on the target molecule with the amine-reactive N-hydroxysuccinimide (NHS) group on the other end of the spacer. The single molecular weight dPEG® spacers have precise length for spatial control. They are hydrophilic and non-immunogenic. The dPEG® spacers improve water solubility and reduce aggregation and precipitation of proteins. The phthalimido protecting group can be removed using hydrazine. The oxyamine group exposed after deprotection can be reacted with an aldehyde- or ketone-containing molecule to form an oxime bond linking the two molecules. These reagents can be used with any protein, peptide, or small molecule that has a free amine. Legal Information Products Protected under U.S. Patents # 7,888,536 B2 dPEG is a registered trademark of Quanta BioDesign