Enzyme-linked immunosorbent assay to quantitate serum ferritin in the northern fur seal (Callorhinus ursinus)

Serum ferritin concentration correlates with tissue iron stores in humans, horses, calves, dogs, cats, and pigs. Serum ferritin is considered the best serum analyte to predict total body iron stores in these species, and is more reliable than serum iron or total iron-binding capacity, both of which may be affected by disorders unrelated to iron adequacy or excess (including hypoprotememia, chronic infection, hemolytic anemia, hypothyroidism, renal disease, and drug administration). Iron overload has been documented to result in hemochromatosis in captive northern fur seals (Callorhinus ursinus); therefore, we developed an enzyme-linked immunosorbent assay (ELISA) to measure serum ferritin in this species. The assay uses two murine anti-canine ferritin monoclonal antibodies in a sandwich arrangement that was originally used in an ELISA to measure serum ferritin in dogs. Ferritin isolated from fur seal liver was used as a standard. Ferritin standards were linear from 0 to 50 ng/ml. Recovery of purified ferritin from fur seal serum varied from 89% to 99%. The within-assay variability was 6%, and the assay-to-assay variability for two different samples was 10% and 16%. (C) 2004 Wiley-Liss, Inc.