The PolarScreen™ Vitamin D Receptor Competitor Assay Kit, Red, provides a sensitive and efficient method for high-throughput, fluorescence polarization-based screening of potential vitamin D receptor (VDR) ligands. The kit uses insect cell-expressed, human full-length VDR (also available separately) and a novel, high-affinity, fluorescent VDR ligand (Fluormone™ VDR Red) in a homogenous, mix-and-read assay format.

This kit produces a red color read-out and is suitable to determine the IC50s of competitive compounds. For additional information or assistance contact us at drugdiscoverytech@lifetech.com.

The PolarScreen Vitamine D Receptor Competitor Assay is:

• Complete & ready-to-use out of the box—all reagents included, just add your test compounds
• High throughput compatible—fluorescence polarization assays in a 384-well plate
• Convenient—components available in bulk sizes for larger screening needs

How the Assay Works
VDR is added to a fluorescent VDR ligand (Fluormone VDR Red) to form a receptor/tracer complex, resulting in a high polarization value. This complex is then added to individual test compounds in microwell plates. Competitors displace the tracer from the complex, causing the fluorescent ligand to tumble more rapidly during its fluorescence lifetime, resulting in a low polarization value. Noncompetitors will not displace the fluorescent ligand from the complex; therefore, the polarization value will remain high. The shift in polarization value in the presence of test compounds is used to determine relative affinity of test compounds for VDR (see figure).

Contact us for bulk quantities or for assistance with other nuclear receptor assay needs, from assay development to library screening and beyond.