A single site serum ferritin immunoradiometric assay. A comparison between serum and liver ferritin standards and two antibody preparations.

A single site immunoradiometric assay (1S-IRMA) for serum ferritin was developed to investigate some standardization problems in the assay of ferritin. In comparison to this 1S-IRMA, a 2-site solid phase IRMA gave lower answers of serum ferritin in the normal reference range, as well as in serum from idiopathic hemochromatosis patients. Purified serum ferritin or liver ferritin gave different standard curves in this new immunoassay system and the differences obtained were further dependent on the antibody preparation employed. The different isoferritin profiles obtained, dependent on the antibody preparation employed for ferritin purification, indicate a different antibody specificity for different ferritin subunits. Serum ferritin purified from different serum pools from healthy persons showed similar isoferritin profiles and immunoassay reactivities.