This nuclear receptor assay utilizes proprietary non-human mammalian cells engineered to provide constitutive, high-level expression of Rat Farnesoid X Receptor (nr1h4), a ligand-dependent transcription factor referred to herein as rFXR. INDIGO’s Reporter Cells include the luciferase reporter gene functionally linked to an FXR-responsive promoter. Thus, quantifying changes in luciferase expression in the treated reporter cells provides a sensitive surrogate measure of the changes in FXR activity. The principle application of this assay is in the screening of test samples to quantify any functional activity, either agonist or antagonist, that they may exert against rat FXR. FXR Reporter Cells are prepared using INDIGO’s proprietary CryoMite™ process. This cryo-preservation method yields exceptional cell viability post-thaw, and provides the convenience of immediately dispensing healthy, division-competent reporter cells into assay plates. There is no need for cumbersome intermediate treatment steps such as spinand-rinse of cells, viability determinations, cell titer adjustments, or the pre-incubation of reporter cells prior to assay setup. INDIGO Bioscience’s Nuclear Receptor Assay kits are all-inclusive cell-based assays. In addition to rFXR Reporter Cells, this kit provides two optimized media for use during cell culture and in diluting the user’s test samples, a reference agonist, Luciferase Detection Reagent, and a cell culture-ready assay plate. [INDIGO Catalog No. R00601]WARNING This product is not for human or veterinary use.