A Monoclonal Antibody for Detecting Ractopamine Technology Description: This invention is for a new ARS-developed monoclonal antibody that is specific for ractopamine. Ractopamine is a feed additive used to increase lean muscle mass in some livestock species. Ractopamine is sometimes used outside of label instructions. Off-label use of ractopamine in food animals could lead to food safety problems. Once further developed into a test kit, it can be used as a rapid, accurate, convenient cost-effective screening test to determine whether or not animals have been exposed to ractopamine. The kit would enable regulatory agencies, livestock show organizers, packing plant officials, and athletic officials worldwide to test live animals, carcasses, and/or humans on-the-spot for exposure to ractopamine. Reference: Please refer to Patent Number 6,274,298, "A Monoclonal Antibody Based Immunoassay for Ractopamine," which issued August 14, 2001. Inventors: Weilin L. Shelver Animal Metabolism-Agricultural    Chemicals Research Unit Fargo, ND 58105-5674 (701) 239-1425 / Fax: (701) 239-1430 shelver@fargo.ars.usda.gov David J. Smith (Same as first inventor) (701) 239-1238 / Fax: (701) 239-1430 smithd@fargo.ars.usda.gov