This nuclear receptor assay system utilizes a proprietary rodent cell line that is further engineered to express the mouse/rat peroxisome proliferator-activated receptor gamma (NR1C3, PPARG). Because the receptor’s ligand binding domain sequence is conserved between mouse and rat species, the receptor is denoted herein as mrPPARγ. These mrPPARγ reporter cells incorporate a responsive luciferase reporter gene, therefore, quantifying expressed luciferase activity provides a sensitive surrogate measure of mrPPARγ activity in the treated cells. The principal application of this reporter assay system is in the screening of test samples to quantify any functional activity, either agonist or antagonist, that they may exert against mrPPARγ. mrPPARγ reporter cells are prepared using INDIGO’s proprietary CryoMite™ process. This cryo-preservation method yields high cell viability post-thaw, and provides the convenience of immediately dispensing healthy, division-competent reporter cells into assay plates. There is no need for intermediate spin-and-wash steps, viability determinations, or cell titer adjustments. INDIGO Bioscience’s nuclear receptor reporter assays are all-inclusive cell-based assay systems. In addition to mrPPARγ reporter cells, this kit provides two optimized media for use in thawing the frozen cells and in diluting the user’s test samples, a reference agonist, luciferase detection reagent, and a cell culture-ready assay plate.