A sandwich enzyme-linked immunosorbent assay for the quantitation of human plasma ferritin

There is a lack of published enzyme linked immunosorbent assay (ELISA) protocols which use commercially available reagents for the measurement of ferritin in human plasma for research purposes. ELISA kits are often expensive and do not always provide detailed information about reagents included. A commercially available antibody pair was used to develop an in-house ELISA to measure ferritin in small (25 μl) volumes of human plasma. ELISA results were compared to ferritin levels measured using a commercial immune-assay system. The sensitivity, intra and inter assay variation of the ELISA assay were also determined. ELISA measurements of plasma ferritin ranged between 3.2–232 ng/mL and were comparable to those measured by a commercial immunoassay system (Pearson correlation r = 0.93 P < 0.0001). Ferritin levels as low as 0.5 ng/mL were detectable and samples with both low and normal ferritin levels showed low inter and intra-assay variation. This ELISA protocol allows the accurate, reliable and cost-effective quantitative determination of plasma ferritin levels from small volumes of human plasma. • No published protocols detail how to measure ferritin by ELISA using commercially available antibodies. • ELISA kits are expensive and information on antibodies included are often lacking. • We have identified a commercially available antibody pair to measure plasma ferritin using a cost-effective ELISA.