Submitted to: Food and Agricultural Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 14, 2008
Publication Date: March 1, 2009
Citation: Brandon, D.L., Hernlem, B.J. 2009. Development of monoclonal antibodies specific for Ricinus agglutinins. Food and Agricultural Immunology. 20(1):11-22 Interpretive Summary: Ricin is a highly toxic protein found in castor beans, and has been used for experimental cancer chemotherapy as well as for intentional poisoning. Because of the latter threat, there is a need for analytical methodology to quantify ricin in both castor extracts and food matrices. We developed a panel of monoclonal antibodies to ricin and found that they were effective in various analytical formats and in a matrix of 25% skim milk. This library of antibodies should be useful in developing methodology for rapid and specific detection of ricin in other food matrices.
Technical Abstract: Ricin is a highly toxic, dichain ribosome-inactivating protein present in the seeds of Ricinus communis (castor), grown principally as a source of high quality industrial lubricant and as an ornamental. Because of its presence in industrial byproducts and its documented use for intentional poisoning, there is a need for analytical methodology to quantify ricin in both castor extracts and food matrices. We developed a panel of monoclonal antibodies to ricin, with most having strong cross-reactivity with RCA-1, a homologous but less toxic castor agglutinin. Some of the IgM-producing hybridomas appeared to produce a second IgG isotype and were further analyzed by fluorescence-activated cell sorting. The antibodies were effective in various ELISA formats, many with IC50’s in the range of 0.1-10 ng/mL and minimal matrix effects in skim milk. Assay specificity can be adjusted for analytical needs by varying the combination of antibodies in a sandwich ELISA format.