Radioimmunoassay of serum ferritin.

Publisher Website
Google Scholar
Abstract
Purified human spleen ferritin was labeled with 125I. On Sepharose 6-B gel filtration 4 species of labled products were separated: a component with a higher MW than ferritin; a component which is eluted in the same volume as unlabeled ferritin; and 2 labeled compounds with MW lower than ferritin. When these labeled materials were used in a double antibody radioimmunoassay, the high MW fraction showed variable and high non-specific binding and was poorly displaced by unlabeled ferritin; the fraction behaving like true ferritin gave good standard curves and showed non-specific binding of less than 1%. The remaining 2 components showed poor binding to rabbit antiferritin. Using labeled material from the 2nd fraction, a double antibody radioimmunoassay capable of measuring 2 .mu.g ferritin protein/l of serum was developed. Inter- and intra-assay variation was between 3%-8% over a concentration range of 0-250 .mu.g ferritin protein/l. Good agreement between serum ferritin levels assayed by the present method and by an immunoradiometric method was obtained. Labeled ferritin was stable for at least 6 wk. The simplicity of the methodology makes it possible to assay serum ferritin in large batches.

This publication has 17 references indexed in Scilit: