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.