Hydrazide-activated agarose beads permit the coupling of aldehyde- or ketone-containing ligands through the formation of stable hydrazone linkages. It is a particularly powerful way to immobilize glycoproteins via their carbohydrate chains, while leaving critical active sites intact. It is a method so called “site-directed immobilization”. For example, antibodies can be immobilized to an agarose solid support through a linkage to their glycosylated side chain, which leaves their Fab region free for antigen binding.
Glycoproteins can be readily oxidized with sodium periodate to generate formyl groups on their carbohydrate chains before the coupling reaction with Hydrazide-activated agarose beads. It is a successful and well-documented technique. The coupling reaction is mild and easy to carry out. No toxic chemical or special equipment is required.
Protein Ark’s Fastback Hydrazide-activated 4 High Flow Resin can be readily employed to make custom affinity chromatography media for both small scale and large scale purification applications.