The reagents and materials provided in this assay kit for the expression profiling of clinically relevant CYPs are formatted to allow for two alternative cell culture setups. In one scenario 48 culture wells may be setup at two different times. In the other assay scenario 96 culture wells may be setup at one time. The kit includes two aliquots of upcyte hepatocytes, donor 10-03, isolated from an adult Caucasian female. These hepatocytes are cryopreserved using INDIGO’s proprietary CryoMite™ process, which yields high cell viability post-thaw, and provides the convenience of immediately dispensing cells into assay plates. There is no need for intermediate treatment steps such as spin-and-rinse of cells, viability determinations, or cell titer adjustments prior to assay setup. During an overnight culture period for cell recovery the hepatocytes will form a confluent monolayer that is ready to receive treatment media containing the user’s test compounds.