Glycosyl composition analysis was performed on a shellfish glycoprotein. The sample was analyzed for monosaccharide composition by preparing the trimethylsilyl derivatives of the methylglycosides followed by gas chromatography (GC) and combined gas chromatography/mass spectrometry (GC-MS) analysis. TMS methylglycosides were prepared from the sample by methanolysis in 3 M HCl followed by N-acetylation with pyridine and acetic anhydride. The sample was then treated with Tri-Sil. GC analysis of the TMS methylglycosides was done on an HP5890 GC using a DB1 fused silica capillary column. GC-MS analysis was performed using an HP5890 GC coupled to a 5970 MSD. Monosaccharides were identified by their retention times in comparison to standards, and the carbohydrate character of these was authenticated by their mass spectra.