By Brad Larson, Peter Banks, Timothy Moeller, and James J Cali
The ability to monitor CYP induction, inhibition, and cytotoxicity by xenobiotics using an automated, multiplexed format can decrease workloads and increase data confidence. Here we demonstrate the ability to monitor CYP1A and -3A induction, combined with a cytotoxicity measurement, from a single well using cryopreserved human hepatocytes. The assay procedure was automated in 96- and 384-well formats, including cell manipulations, compound titration and transfer, and reagent dispensing, using simple, yet robust robotic instrumentation. EC50 values were derived for multiple known inducers of CYP1A and -3A from an 11-point curve. Induction and toxicological responses in the triplex system were validated based on consistency with conventional single parameter assays. Validation and pharmacology data confirm that multiplexed cell-based CYP assays can simplify workload, save time and effort, and generate the data needed from today's ADME/Tox laboratory.