Biotin-PEG4-NHS Ester

Biotin-PEG4-NHS Ester reacts specifically and efficiently with primary amines (e.g., a side chain of lysine residues or aminosilane-coated surfaces) at pH 7-9 to form covalent bonds. The hydrophilic polyethylene glycol (PEG) spacer arm of this reagent imparts water solubility that is transferred to the labelled molecule, thus reducing aggregation of labelled proteins stored in solution. The PEG spacer arm also gives the reagent a long and flexible connection to minimise steric hindrance involved with binding to avidin molecules.