Crossed affino-immunoelectrophoresis or affino-blotting with lectins: advantages and limitations for glycoprotein studies.

In contrast to the conventional combination of physical, chemical and enzymatic methods used for a structural analysis of glycans in glycoproteins, alternative methods involve affinity electrophoresis as a tool for the detection, characterization, and quantitation of glycoproteins and their carbohydrate moiety, owing to interactions with lectins. Two major approaches involve (i) crossed affino-immunoelectrophoresis and variations thereof, whereby lectin/glycoprotein interactions occur during the electrophoretic runs, or (ii) affino-blotting, where the glycoproteins are electrophoretically separated and then immobilized onto a solid support prior to their interaction with lectins. A critical comparison of these two series of techniques is the scope of the present paper. These techniques are of high interest by virtue of their ability at differentiating a classical glycan structure from unusual oligosaccharide side chains. The former structures will usually be qualitatively and quantitatively described with the easy and fast procedures as well as the simple equipment required for crossed affino-immunoelectrophoresis or affino-blotting, whereas the latter will be good candidates for further structural analyses.