Methods for the determination of the specific radioactivity of radioligands

Quantitative analysis of radioligand binding data requires the knowledge of an accurate and actual value for the specific radioactivity of the radiolabeled ligand. Several protocols, based on simple radioligand binding experiments, which allow the determination of the molar assay concentration of the radioligand and of the radioligand/receptor complex, are described. Their appropriateness is demonstrated by the use of tritiated and iodinated beta-adrenergic radioligands.