DBCO-PEG5-NHS Ester

DBCO-PEG5-NHS Ester reacts specifically and efficiently with a primary amine (e.g., side chain of lysine residues or aminosilane-coated surfaces) at pH 7-9 to form a covalent bond. The hydrophilic polyethylene glycol (PEG) spacer arm imparts water solubility that is transferred to the labeled molecule, thus reducing aggregation of labeled proteins stored in solution. The PEG spacer arm provides a long and flexible connection that minimizes steric hindrance involved with ligation to complementary azide-containing molecules.