There are two common strategies that are adopted for this type of experiment:[REF] Increasing the amount of radioligand added while maintaining both the constant specific activity and constant concentration of radioligand, or decreasing the specific activity of the radioligand due to the addition of an unlabeled ligand [REF].
Competition Binding is used to determine the presence of selectivity for a particular ligand for receptor sub-types, which allows the determination of the density and proportion of each sub-type in the tissue [REF].