Biotin-LC-LC has an extended spacer and a activated NHS ester in the end. The extended spacer helps minimize steric hindrance to the conjugate and the membrane permeability of this reagent allows it to be used for intracellular labeling. NHS ester reacts efficiently with amino (-NH2) bearing proteins, lysine residues and other amine containing biopolymers to form stable, irreversible amide bonds.
Axispharm offers 3000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.