Competitive binding assays made easy with a native marker and mass spectrometric quantification

MS makes it possible: Competitive binding assays are a widely used tool in drug research to characterize the affinity of a ligand for a biological target. However, these assays generally require special ligands which can be detected with high sensitivity, such as radioligands or ligands coupled to a fluorophore. Now native markers may be employed in conjunction with mass spectrometric quantification. First studies demonstrate this approach in binding experiments at dopamine D1-receptors.