Microheterogeneity and polymorphism of human serum thyroxine-binding globulin study by isoelectric focusing and radioprint immunofixation

Abstract A new technique of radioprint immunofixation following isoelectric focusing was applied to the study of microheterogeneity of thyroxine-binding globulin without purification, in individual sera; this protein appeared to give rise to at least seven bands with isoelectric points in the range of p I 4.2–5.0. Furthermore, two different distributions of the intensity of these bands were found in the sera investigated, suggesting the existence of thyroxine-binding globulin polymorphism in man.