Improved method for fluorescence labeling of suger chains with sialic acid residues.

The pyridylamination methodis useful for the structural analysis of sugar chains from small amountsof glycoproteins. About 60% of the sialyl linkage was, however hydrolyzed under the reaction conditions reported previously.1>2) The growing need for fluorescence labeling oi sialyl sugar chains prompted us to re-investigate the reaction conditions.