Methyltetrazine-PEG4-NHS Ester

Methyltetrazine-PEG4-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 PEG spacer arm provides a long and flexible connection that minimizes steric hindrance involved with ligation to complementary TCO-containing molecules. The aqueous solubility of this reagent is substantially enhanced by a hydrophilic polyethylene glycol (PEG) spacer arm.