Patent ID: 8772044

Claim:
A method of negative-ion MALDI analysis of neutral labeled sugar chain comprising the steps of: preparing a sample containing a neutral sugar chain; labeling the neutral sugar chain with a labeling compound having a fundamental skeleton of aromatic selected from the group consisting of pyrene, benzene, and pyridine and comprising at least one selected from the group consisting of amino group and carboxylic acid hydrazide group to obtain a neutral labeled sugar chain; wherein the neutral sugar chain contains fucose; or preparing a sample containing an acidic sugar chain; neutralizing and labeling the acidic sugar chain with a labeling compound having a fundamental skeleton of aromatic selected from the group consisting of pyrene, benzene, and pyridine to obtain a neutral labeled sugar chain; wherein the acidic sugar chain contains sialic acid; and subjecting the neutral labeled sugar chain to negative ion MALDI analysis.