Patent ID: 8691795

Claim:
A method of analyzing the structure of an oligosaccharide derived from cancer cells in an oligosaccharide mixture containing sialo oligosaccharides, comprising the steps of (a) introducing a lipophilic group to oligosaccharides in the mixture to obtain a mixture of oligosaccharide derivatives, wherein the lipophilic group is selected from the group consisting of 2-carboxyphenylamino, 3-carboxyphenylamino, 4-carboxyphenylamino, p-ethoxycarbonylphenylamino, 2-pyridylamino, 9-fluorenylmethoxycarbonyl (Fmoc), tert-butoxycarbonyl (BOC), benzyl, allyl, allyloxycarbonyl, and acetyl; (b) treating the lipophilic group-modified oligosaccharide derivative mixture to serotonin affinity column chromatography to obtain fractions each containing oligosaccharide derivatives having the same number of sialic acid(s); (c) treating each fraction obtained in step (b) to normal-phase chromatography using an amino column or amide column; and (d) analyzing the oligosaccharide derivative contained in each fraction obtained in step (c) by a mass spectrometric method.