Solid-Phase Oligosaccharide Tagging: A technique for manipulation of immobilized carbohydrates

The invention relates to methods of manipulating immobilised carbohydrates by de-rivatisation. Depending on the nature of the derivatisation, the carbohydrate may thereby be more easily detected and/or identified or handled. In particular, the inven-tion relates to methods of preparing a reactive sugar comprising the steps of: i) pro-viding a sample comprising a reducing sugar; ii) providing a solid support covalently attached to a linker comprising a capture group comprising an -NH2 group, wherein said linker optionally is attached to said solid support via a spacer; iii) reacting said reducing sugar with said -NH2 group, thereby obtaining an immobilised sugar; iv) reacting free -NH2 groups with a capping agent, wherein the capping agent com-prises a reactive group capable of reacting with an -NH2 group; and v) reducing C=N bonds with a reducing agent, thereby obtaining an reactive sugar of the struc-ture SugarCHn-NH- linked to a solid support via a linker and optionally a spacer, wherein n is 1 or 2.