Detection of cyclopiazonic acid (CPA) in maize by immunoassay

We report the development and evaluation of several monoclonal antibodies (mAbs) for α-CPA. Two mAbs in particular were very sensitive, with IC50s of 1.1 and 1  ng/mL (clones 1418 and 1231, respectively). Tolerances to aqueous methanol or acetonitrile were good, which permitted the development of an antigen-immobilized competitive enzyme-linked immunosorbent assay (CI-ELISA) for detection of CPA in maize. Spiked or naturally contaminated maize, extracted with aqueous methanol, was diluted with buffer for analysis. The working range for the assay (IC20 to IC80) was from 5 to 28  μg/kg. Recoveries from maize spiked over the range from 2 to 50 μg/kg averaged 88.6 ± 12.6%. Twenty-eight samples of maize were tested by both the CI-ELISA and a liquid chromatography-fluorescence (LC-FLD) method. For the five samples above the limits of quantitation of both methods, CI-ELIS A tended to overestimate CPA content, a difference that we speculate may be due to related metabolites or perhaps “masked” derivatives of CPA. The antibodies developed and the resulting CI-ELISA will be useful tools for further evaluation of the prevalence of this mycotoxin in maize.

Source: Mycotoxin Research - April 5, 2017 Category: Toxicology Source Type: research