Glycoproteins were fractionated from serum using the different lectin spin columns in glycoprotein fractionation kits and analyzed by SDS-PAGE followed by silver staining. [A] Elution steps 1–3 and 4–6 from Total Lectin Spin Columns in the Total Glycoprotein Kit. [B] Eluted glycoproteins from ConA, GNA, and LCH Spin Columns in the Mannose Glycoprotein Kit. [C] Eluted glycoproteins from WGA, SNA, and MAL Spin Columns in the Sialic Glycoprotein Kit. [D] Eluted glycoproteins from AIL and PNA Spin Columns in the O-Glycan Glycoprotein Kit.