The RARβ Reporter Cellular Assay Pack provides all the key reagents required to monitor the activity of retinoic acid receptor beta (RARβ). The pack contains the RARβ Reporter (Luc)-HEK293 Cell Line, a luciferase reporter cell line that contains a firefly luciferase gene under the control of retinoic acid response elements stably integrated into HEK293 cells along with full length human RARα (GenBank Accession No. P10826-2). This cell line is functionally validated for the response to the stimulation of all-trans retinoic acid, and the expression of RARβ is confirmed by Western blotting.Additionally, the pack includes cell culture medium (Thaw Medium 6) that has been optimized for use with HEK293 cells. Thaw Medium 6 includes 10% fetal bovine serum and 1% Pen/Strep. Finally, the pack provides the ONE-Step™ Luciferase Detection System. This reagent provides highly sensitive, stable detection of firefly (Photinus pyralis) luciferase activity. The ONE-Step luciferase reagent can be used directly in cells in growth medium, and can be detected with any luminometer; automated injectors are not required.