The GeneBLAzer®RAR alpha DA (Division Arrested) and RAR alpha-UAS-bla HEK 293T cells contain the ligand-binding domain (LBD) of the human retinoic acid receptor alpha fused to the DNA-binding domain of GAL4 stably integrated in the GeneBLAzer®UAS-bla HEK293T cell line. GeneBLAzer®UAS-bla HEK 293T cells (catalog#K1104) stably express a beta-lactamase reporter gene under the transcriptional control of a 7x Upstream Activator Sequence (UAS). Transcription from the 7xUAS is activated by the binding of the GAL4 transcription factor DNA-binding-domain (DBD). The GAL4-DBD is expressed as a fusion protein with the ligand binding domain (LBD) of RAR alpha. When an agonist binds to the LBD of the GAL4(DBD)-RAR alpha(LBD) fusion protein it translocates to the nucleus where it binds to the 7x UAS inducing transcription of beta-lactamase. Division Arrested (DA) cells are available in an Assay Kit (which includes cells and sufficient substrate to analyze 1 x 384-well plate). DA cells are irreversibly division arrested using a low-dose treatment of Mitomycin-C, and have no apparent toxicity or change in cellular signal transduction. Both RAR alpha DA cells and RAR alpha-UAS-bla HEK 293T cells have been tested for assay performance using variable assay conditions, including DMSO concentration, cell number, stimulation time, substrate loading time and have been validated for Z' and EC50 concentrations of all-trans retinoic acid. Additional testing data using alternate stimuli are also available.