Biotin-PEG23-amine is PEG derivative containing an extended PEG spacder between the biotin and amine end groups. The amine group can undergo coupling with to carboxylic acid and activated ester bearing biomolecules to form stable amide bond. The PEG spacer increases solubility of the resulting complex in aqueous media. The PEG spacer may also help minimize steric hindrance from the binding to streptavidin and avidin.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.