Every PolarScreen™ Competitive Binding Assay for Nuclear Receptors includes protein, a proprietary fluorescent Fluormone™ ligand, and an optimized buffer system. When the NR binds to the Fluormone™ ligand, the resulting complex yields a high polarization value. If the test compound displaces the Fluormone™ ligand from the complex, the polarization value is lowered. Since this occurs only in the presence of a test compound, the shift in polarization value enables you to accurately and conveniently determine relative affinity of a test compound for the NR.

Figure 1. Fluormone™ ligands are biologically relevant steroid derivatives, designed to achieve nanomolar binding affinities and robust Z’-factors. Development of these Fluormone™ ligands required expert chemistry and manipulation of buffer composition. Assay are optimized for maximum stability of instrumentation platforms, and to tolerate solvents typically found in compound libraries.

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PolarScreen™ Nuclear Receptor Competitive Binding Assays Screening Data

Figure 2. Competition data using the AR Competitor Assay, Green, generated on a 384-well plate. The concentration of the test compound that results in a half-maximal shift in polarization value equals the IC50 of the test compound, which is a measure of the relative affinity of the test compound for the androgen receptor ligand binding domain.
Figure 3. A subset of the Prestwick Bioactive Compound Library (bar code: 28151401), rich in nuclear receptor ligands was screened at 10 µM in the AR Competitor Assay, Green. Approximately 10% of the compounds were identified as hits because they displaced the Fluormone™ AL Green tracer from ARLBD (His-GST), and 1% of the library exhibited interfering compound fluorescence.





For research use only. Not intended for any animal or human therapeutic or diagnostic use.