Radioimmunoassay for a vitamin-d dependent calcium-binding protein in rat duodenal mucosa

Abstract A radioimmunoassay for a vitamin D-stimulated calciumbinding protein from rat intestine has been developed. The assay can measure as little as 0.5 ng protein and has allowed to detect an immunoreactive material in rat serum. On the other hand, no cross-reactivity has been observed with either the protein from rat kidney or that from pig duodenum.