Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/28/2005
Publication Date: 9/6/2005
Citation: Shelver, W.L., Kim, H., Li, Q.X. 2005. Development of a monoclonal antibody based elisa for the beta adrenergic agonist zilpaterol. Meeting Abstract. VIIIth International Conference on AgriFood Antibodies, Sept. 6-9, 2005, Chester, UK.
Interpretive Summary: This is a meeting abstract only.
Technical Abstract: South Africa and Mexico, but neither the EU, USA, nor any Asian country have approved zilpaterol for use as a growth promoter in cattle, making development of a screening assay desirable. Monoclonal antibodies were generated in mice by immunization with zilpaterol-butyrate-KLH, and the same hapten was coupled with BSA for use as a coating antigen for the ELISA. Three clones were selected for further ELISA optimization from thirteen isolated clones after the initial sensitivity and isotyping experiments. The optimum pH was near 7.4. The highest sensitivity to zilpaterol was found for clone 3H5 and this clone had some interaction with high concentrations of clenbuterol and terbutaline, but no interaction with other N-alkyl [bamethane, (-) isoproterenol, (+) isoproterenol, metaproterenol, or salbutamol,] or N-arylalkyl (fenoterol, isoxsuprine, ractopamine, or salmeterol) b-agonists tested. Deleterious effects of high salt concentrations were found, which precluded further development of 3H5. Clone 2E10 did not cross-react with any of the structural analogues tested, but its sensitivity to salt and urine concentration changes could cause high variability. Clone 7A8 showed good sensitivity and demonstrated smaller changes in IC50 and B0 with increasing sheep urine or cattle urine concentrations compared to clones 2E10 or 3H5, and was selected for further development. The IC50 for all the antibodies showed exponential increases with increasing organic solvent concentrations, making it desirable to minimize solvent levels. In conclusion, a sensitive, zilpaterol specific monoclonal antibody based ELISA has been developed that can serve as a rapid screening assay.