High throughput ELISA chip for drug toxicity screening Summary Adverse drug metabolism, drug-drug interactions, and direct toxicity effects have caused numerous drug failures. High throughput biomarker profiling offers the potential to predict drug toxicity to help reduce pipeline attrition. Reaction Biology Corporation has developed extremely low cost nanoliter reaction microarrays to serve markets for ultra high throughput screening (uHTS), large scale IC50 determinations, and selectivity profiling in drug discovery. These reactions are 1000 to 10,000-fold smaller than well plate formats currently used widely in drug discovery. Based on Phase I data demonstrating high sensitivity profiling of cellular antigens, we propose to create microarray products and technologies capable of evaluating drug-induced hepatotoxicity by screening large numbers of cell lysates obtained from cells treated with chemical compounds or their combinations. The following specific aims for Phase II research include: Aim 1 Develop and validate detection protocols for over 30 toxic-biomarkers involved in drug-induced liver toxicity testing. These markers will serve as the basis for the HepTox-chip(r) (hepatocyte toxic biomarkers antibody microarray) and for the Mi-HTS(r) (microarray immunoassay for high throughput screening) service offering. Aim 2 Establish a compound library including common over-the-counter and prescription drugs and test their hepatotoxicity profiles with HepTox-chip(r) and Mi-HTS(r) chip. This aim will be particularly useful for identifying unexpected drug- drug interactions of new chemical entities. Aim 3 Develop the Toxic-Informatics Database (ToxID(r)) by integrating the publicly available information related to biomarkers from Aim 1 in genomic, proteomic and clinic tests with common drugs tested in Aim 2 as a predictive tool for hepatotoxicity. The central goal of the proposed Phase II efforts is to develop two antibody microarray based products, one a marketable and user-friendly microarray chip detecting over 30 protein toxic-biomarkers and the other a service package that RBC provides for analyzing a large number of chemicals effects (e.g. test compound crossed against the OTC/prescription drug library) on hepatocyte toxic biomarker expression. Drug-induced liver toxicity is the major cause of drug-induced death and the principle reason for withdrawal of drugs from the market (Waring, 2003) and Food and Drug Adminstration (FDA) already sees toxicogenomic's potential in proving hypotheses that support safe drug use in humans through a mechanistic understanding of toxicities found in drug-treated animals (Lord & Papoian, 2004). The toxicoproteomic is a relatively new area that could have similar function but with more directed and precisely detection, because monitoring protein expression changes is more relevant than monitoring gene changes (Wetmore & Merrick, 2004; Kikkawa et al, 2006; Yamamoto et al, 2005). [unreadable] [unreadable] [unreadable]