Monoclonal Antibodies for the Mycotoxins Deoxynivalenol and 3·Acetyl.Deoxynivalenol

The mycotoxin deoxynivalenol (DON) is produced by the mold Fusarium graminearum and is found 'worldwide on cereal grains. in particular .vheat and maize. Each year this compound. also known as ....·omitoxin· causes substantial losses to agricultural productivity. Three monoclonal antibodies were developed following the immunization of mice with a conjugate of DON and ovalbumin. One of these antibodies. produced by clone #22 . •vas selected for the development ofa competitive direct ELISA (CD-ELISA). Thisformat consists ofcompetition benveen a DON horseradish peroxidase conjugate (DON-HRP) andfree DON for antibody attached to microwell plates. Color development in the assay was inhibited 50% (IC50) by 18ng DON/ml in phosphote-buffered saline (PBS). The antibody from this clone shmved strong cross-reactivity to 3-acetyl dem}'nivalenol (3-Ac-DON) .•vith an IC50 of 2.9 ng mlI Cross-reactivity to 19 other trichothecene mycotoxins was lOll'. The CD-ELISA was applied to wheat spiked lvith DON over the range 0.01-10 f,Lg/g and extracted with a 1O-fold excess of PBS. The midpoint for color development in the assay using this extraction was 0.27 f,Lg DON/g wheat. Recoveries over the range 0.05-5 f,Lg/g averaged 88.7% 'with a coefficient of variation of 10.9%. This assay is sufficiently sensitive and rapid to permit the screening of DON in ,vheat below the US Food and Drug Administration advisOl}' level of 1ppm in human food.