Combine 2 μl of Fetuin, 1 μl of 10X Glycoprotein Denaturing Buffer, and 5 μl of H2O. Incubate at 95°C for 10 minutes. Add 1 μl of 10X G7 Reaction Buffer and 1 μl of 10% NP-40. Add 1 μl of endoglycosidase. Incubate at 37°C for 1 hour. Visualize reaction products on 10–20% SDS-PAGE gel.