RXR alpha-UAS-bla HEK 293T cells contain the ligand-binding domain (LBD) of the human retinoid X receptor-alpha (RXR alpha) fused to the DNA-binding domain of GAL4 stably integrated in the GeneBLAzer™UASbla HEK 293T cell line. GeneBLAzer™UAS-bla HEK 293T cells stably express a betalactamase reporter gene under the transcriptional control of an upstream activator sequence (UAS). When an agonist binds to the LBD of the GAL4 (DBD)-RXR alpha (LBD) fusion protein, the protein binds to the UAS, resulting in expression of alpha-lactamase. Division Arrested (DA) cells are available in two configurations- an Assay Kit (which includes cells and sufficient substrate to analyze 1 x 384-well plate), and a tube of cells sufficient to analyze 10 x 384-well plates. RXR alpha-UAS-bla HEK 293T cells are functionally validated for Z' and EC₅₀ concentrations of 9-cis-retinoic acid. In addition, RXR alpha-UAS-bla HEK 293T cells have been tested for assay performance under variable conditions, including DMSO concentration, cell number, stimulation time, and substrate loading time (data available upon request). Additional testing data using alternate stimuli are also available.