Detection of Altered Glycosylation of α-Fetoprotein Using Lectin-Affinity Electrophoresis

α-Fetoprotein (AFP) is an oncofetal glycoprotein with a molecular mass of 70,000 Dalton and a carbohydrate content of approx 4%, i.e., one carbohydrate chain per molecule. High concentrations of AFP are found in the fetal serum as well as in amniotic fluid. Serum concentration of AFP in cord blood at birth range from 10,000-100,000 ng/mL, and it becomes suppressed to levels below 10 ng/mL by 300 d after birth (1). AFP is re-expressed frequently in hepatocellular carcinomas and yolk sac tumors, and much less frequently in gastrointestinal carcinomas.