Development of a competitive enzyme linked immuno sorbent assay to measure ceruloplasmin in gamma-irradiated rat serum.

Abstract

The concentrations of ceruloplasmin could not be determined by comparing the oxidase activities toward p-phenylenediamine and o-dianisidine in rat whole serum with those of purified ceruloplasmin because of the different specific amine oxidase activities of ceruloplasmin purified from normal and gamma-irradiated rats and the lability caused by freezing and thawing. A competitive enzyme linked immunosorbent assay with antigens immobilized on the solid phase was developed to measure the ceruloplasmin in rat serum. The blocking materials and pH of the coating buffer had an effect on the amount of ceruloplasmin bound to the microtiter plates. The blocking materials nonspecifically reacted with the rabbit anti-rat ceruloplasmin IgG, and consequently the coating sensitivity was decreased and standard curves were not formed completely. Because rabbit anti-rat ceruloplasmin IgG did not show any cross reactivity with rat albumin and hemoglobin, these proteins did not affect the assay at a concentration of 200 micrograms/ml. This assay is useful for measuring the concentration of ceruloplasmin in normal and irradiated rat serum.