Labeled Dehydroxy Ractopamine. Monoclonal antibody hybridoma immunoassay Ractopamine. Ractopamine is a veterinary drug, now considered illegal. A beta-adrenoceptor agonist, binding to muscle cell membrane receptors, resulting in increased protein synthesis and increased muscle fibers.Form:Off-White SolidMelting Point:250-252°CSolubility:DMSO, Methanol