The Drug Matrix reference library is a toxicogenomic reference resource of scientists in the field of toxicology. THe database is comprised of transcriptomic data from rats treated with over 600 test agents. The transcriptomic data in the original library was largely comprised of Affymetrix microarray data; as other technologies have taken over in the field, and in use by the Division of Translational Toxicology there was a desire by the division to utilize residual tissue and isolated RNA from the rat studies and produce S1500+ and whole transcriptome TempOSeq data to add to the database.