The GenomeLab GeXP Rat MultitoxPlex Kit for for the GenomeLab GeXP Genetic Analysis System (both Beckman Coulter, Inc.) contains 25 genes involved in pathways for toxicity, stress, DNA damage and apoptosis. Three reference genes and one internal standard are also included. The kit and the GeXP System deliver multiplexed quantitative analysis of genes from hundreds of samples at a time, providing high throughput. The assays run in 96-well plate format, for screening large compound libraries. Researchers may add their own genes of interest panel. The GeXP system analyzes up to 30 genes in one reaction.