In order to locate sites of glycosylation, we employ a glycocapture protein fractionation step and/or Differential 2-D gel electrophoresis (DIGEā„¢) with a glycoprotein specific (Pro-Q Emerald, Invitrogen) gel stain. Different digestions/cleavages (e.g. trypsin, CNBr, LysC, and Protease XIII) are utilized prior to glycocapture in order to maximize detection of the glycopeptides for glycoside determination.

Figure 1 shows differences between PNGase and Endo H treatments for glycan analysis on the FT-ICR mass spectrometer.