A Monoclonal Antibody Based Capture ELISA for Botulinum Neurotoxin Serotype B: Toxin Detection in Food |
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Authors: | Larry H. Stanker Miles C. Scotcher Luisa Cheng Kathryn Ching Jeffery McGarvey David Hodge Robert Hnasko |
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Affiliation: | 1.Foodborne Toxin Detection and Prevention Unit, United States Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, CA 94510, USA; E-Mails: (M.C.S.); (L.C.); (K.C.); (J.M.); (R.H.);2.DuPont Industrial Biosciences, Palo Alto, CA 94304, USA;3.United States Department of Homeland Security, Washington, DC 20528, USA; E-Mail: |
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Abstract: | Botulism is a serious foodborne neuroparalytic disease, caused by botulinum neurotoxin (BoNT), produced by the anaerobic bacterium Clostridium botulinum. Seven toxin serotypes (A – H) have been described. The majority of human cases of botulism are caused by serotypes A and B followed by E and F. We report here a group of serotype B specific monoclonal antibodies (mAbs) capable of binding toxin under physiological conditions. Thus, they serve as capture antibodies for a sandwich (capture) ELISA. The antibodies were generated using recombinant peptide fragments corresponding to the receptor-binding domain of the toxin heavy chain as immunogen. Their binding properties suggest that they bind a complex epitope with dissociation constants (KD’s) for individual antibodies ranging from 10 to 48 × 10−11 M. Assay performance for all possible combinations of capture-detector antibody pairs was evaluated and the antibody pair resulting in the lowest level of detection (L.O.D.), ~20 pg/mL was determined. Toxin was detected in spiked dairy samples with good recoveries at concentrations as low as 0.5 pg/mL and in ground beef samples at levels as low as 2 ng/g. Thus, the sandwich ELISA described here uses mAb for both the capture and detector antibodies (binding different epitopes on the toxin molecule) and readily detects toxin in those food samples tested. |
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Keywords: | monoclonal antibodies botulinum neurotoxin serotype B capture ELISA toxin detection in food |
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