MONOCLONAL-ANTIBODIES FOR THE ENZYME-IMMUNOASSAY OF THE MYCOTOXIN CYCLOPIAZONIC ACID

Murine monoclonal antibodies (MAB) were raised from hybridomas obtaine d by fusions of splenocytes from Balb/c mice immunized intraperitoneal ly with cyclopiazonic acid-keyhole limpet hemocyanin (CPA-KLH) conjuga tes, with different myeloma lines. Hybridomas secreting antibodies aga inst CPA were detected by enzyme immunoassay, purified by limiting dil ution cloning, and adapted to a batch fermentation process for the lar ge-scale production of MAB. From 15 independent hybridomas obtained, 1 was used further. MAK S14-2-B6 (IgG1) is extremely selective for cycl opiazonic acid (the only cross-reactant detected so far is cyclopiazon ic acid imine, which displays a cross-reaction of 20%) and can be used in an antibody-immobilized enzyme immunoassay format measuring from 7 to 300 ng per assay of the mycotoxin. The intra-assay coefficient of variation is 2.5%, and inter-assay variability is 4.4% (within-day) an d 8.1% (between-day). Crude extracts from fungal strains can be analyz ed for CPA, thus allowing an efficient screening of fungal isolates fo r toxin production. The assay can be used to analyze white-mold fermen ted cheese for CPA.