Semiautomated High-Sensitivity Profiling of Human Blood Serum Glycoproteins through Lectin Preconcentration and Multidimensional Chromatography/Tandem Mass Spectrometry

We describe an effective analytical approach to identify trace glycoproteins in a small volume of human serum. The system is based on automatable affinity enrichment through silica-based lectin microcolumns and a further separation of the retained glycoproteins on a reversed-phase liquid chromatography with superficially porous packing, operating at high temperature. The fractionated sample is further directed into a 96-well plate for trypsinization and LC−MS/MS analysis. Using a major-component depleted blood serum (16 μg total protein), we were able to identify 271 glycoproteins through this analytical system.