Abstract: Methods of analyzing glycosylated biomolecules include the steps of producing a deglycosylation mixture of biomolecules deglycosylated by natural or synthetic enzymatic or chemical techniques; providing a reagent solution having a labeling reagent in a polar aprotic, non-nucleophilic organic solvent; and mixing the deglycosylation mixture with the reagent solution in an excess of labeling reagent to produce derivatized glycosylamines. The method steps can be carried out purposefully without depletion of protein matter. A quenching solution can be added to the reaction mixture so that the pH of the reaction mixture is shifted to above 10. The yield of derivatized glycosylamines can be in an amount of about 80 to about 100 mole percent of the reaction mixture with minimal overlabeling, less than 0.2 mole percent.