Biotin-PEG9-NHS Ester contains a biotin group and an NHS ester group. The PEG spacer increases the aqueous solubility of the resulting compound. The NHS group readily reacts with lysine and N-terminal amino groups at pH 7-9 and forms stable amide bonds. The PEG spacer arm provides flexibility and minimize steric hindrance for binding to streptavidin and avidin.
Axispharm offers 3000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.