VDR-UAS-bla HEK 293T cells contain the ligand-binding domain (LBD) of the human Vitamin D receptor (VDR) fused to the DNAbinding domain of GAL4 stably integrated in the GeneBLAzer™UAS-bla HEK 293T cell line. GeneBLAzer™UAS-bla HEK 293T cells stably express a beta-lactamase reporter gene under the transcriptional control of an upstream activator sequence (UAS). When an agonist binds to the LBD of the GAL4 (DBD)-VDR (LBD) fusion protein, the protein binds to the UAS, resulting in expression of beta-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. VDR-UAS-bla HEK 293T cells are functionally validated for Z' and EC₅₀ concentrations of Calcitriol (1α, 25-dihydroxyvitamin D3). In addition, VDR-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.