Immunoradiometric Assay IRMA of Ferritin with Bead Separation

Immunoradiometric Assay (IRMA) of Ferritin with Bead Separation 

Functionally, ferritin, in conjunction with transferrin, regulates the movement of iron from the gastrointestinal tract to various tissues responsible for iron storage as well as to the bone marrow. 

The ferritin found in each tissue has a characteristic structure, and exists as isoferritin. Of special interest is the serum ferritin, which is considered to be different from any specific isoferritin. The serum ferritin level reflects the iron status of the body. 

More detailed information to ferritin is given by Crichton (1973) and Jacobs et al. (1975). 

The RIA-gnost Ferritin kit (no more commercially available) from formerly Behringwerke AG, Radiochemical Laboratory described below uses the principle of an immunoradiometric assay (IRMA). It is a two-site solid phase assay of the sandwich type, based on a plastic bead as solid phase to which the antiferritin antibody adheres. The antibody-solid phase is incubated with standards or serum samples containing ferritin and in this process the ferritin in the solution is bound quantitatively to the solid phase via the antibody. The amount of ferritin bound to the solid phase is then determined by a reaction with 125I-labeled anti-ferritin antibody. An antibody-ferritin-125I-antibody complex is thus formed. 

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