Molecular Size of Carcinoembryonic Antigen in the Plasma of Patients With Malignant Disease

Summary

Plasma from patients with various malignancies was chromatographed by gel filtration, and the molecular size of carcinoembryonic antigen (CEA) was determined. As measured by the Hansen Z-gel radioimmunoassay, the circulating antigen was heterogenous in molecular size. The CEA in the plasma of patients with cancers of the colon, ovary, cervix, and bronchus had a molecular size of ≈370,000 daltons, whereas CEA in the plasma of rectal-tumor patients was 200,000 daltons.