Detection of zearalenone and related metabolites by fluorescence polarization immunoassay.
Zearalenone is an estrogenic mycotoxin commonly found in grains throughout the world. A number of instrument- and antibody-based methods including enzyme-linked immunosorbent assays (ELISAs) have been developed to detect zearalenone (ZEN) and related toxins in commodities and foods. Although convenient, the commercial ELISAs for small molecules such as ZEN require a washing step to separate bound and unbound enzyme label before detection. In fluorescence polarization immunoassays, separation of bound and unbound label is not required, a property that reduces the time needed to perform the assays. We developed a fluorescence polarization immunoassay for ZEN in maize. When combined with a rapid extraction technique, the assay could be used to detect as little as 0.11 microg of ZEN g(-1) maize within 10 min. The assay showed cross-reactivity to the ZEN analogs zearalanone, alpha-zearalanol, alpha-zearalenol, beta-zearalenol, and beta-zearalanol of 195, 139, 102, 71, and 20%, respectively, relative to ZEN (100%). Recovery of ZEN from spiked maize over the range of 0.5 to 5 microg g(-1) averaged 100.2% (n = 12). The fluorescence polarization immunoassay results were comparable to those obtained with a liquid chromatographic method for the analysis of 60 naturally contaminated maize samples and maize samples amended with culture material. The fluorescence polarization immunoassay provides a rapid method for screening of maize for ZEN.
Maragos
Chris M
CM
Mycotoxin Research Unit, National Center for Agricultural Utilization Research, U.S. Department of Agriculture, Agricultural Research Service, 1815 North University Street, Peoria, Illinois 61604, USA. maragocm@ncaur.usda.gov
Kim
Eun-Kyung
EK
D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003257:Consumer Product Safety; D004305:Dose-Response Relationship, Drug; D002523:Edible Grain / Q000737:chemistry* / Q000382:microbiology*; D016231:Fluorescence Polarization Immunoassay / Q000379:methods*; D005516:Food Microbiology; D012680:Sensitivity and Specificity; D013997:Time Factors; D003313:Zea mays / Q000737:chemistry / Q000382:microbiology; D015025:Zearalenone / Q000032:analysis / Q000302:isolation & purification*
D015025:Zearalenone