Fig. 3
From: Glycomic profiling of carcinoembryonic antigen isolated from human tumor tissue
MALDI-TOF MS profiles of the permethylated N-linked glycans from CEA of colorectal carcinoma patients. All molecular ions are present in singly charged sodiated form ([M + Na]+). In the glycan structure, blue square refers to N-acetylglucosamine (■), green circle refers to mannose (●), yellow circle refers to Galactose (●), red triangle refers to Fucose (▲), and purple diamond refers to N –acetylneuraminic acid (♦). a-e refers to mass spectrum of CEA glycans in different mass range