Simple radioimmunoassay for transferrin using insolubilized antitransferrin antibodies: its application to cultured...

A radioimmunoassay (RIA) for transferrin is described. The assay uses antitransferrin antibodies covalently coupled to the particulate support Matrex Pel 102, and is simple, sensitive, reproducible, and rapid. Transferrin measurement with this assay is independent of the degree of iron saturation of the protein. The RIA was applied to the measurement of transferrin concentrations in a variety of cultured human cells. Each of 11 cell lines studied contained endogenous transferrin, but the greatest concentration was found in Chang liver cells. Red blood cells were used as a negative control.