Comparison of homogeneous single-label fluorometric binding assays: fluorescence polarization and dual-parametric quenching resonance energy transfer technique.

The time-resolved fluorescence technique, quenching resonance energy transfer, QRET, relies on a single-labeled binding partner in combination with a soluble quencher. The quencher reduces efficiently the fluorescence of the unbound labeled ligand, whereas the fluorescence of the bound fraction is detectable. This approach allows the development of homogeneous screening assays in a simple and cost-effective manner.