title: Development of a portable field immunoassay for the detection of aflatoxin M1 in milk.
abstract: Many methods for AFM1 detection exist, but most are time consuming, employ expensive equipment and require experienced personnel. To overcome these problems a membrane-based flow-through enzyme immunoassay has been developed (patent pending). The assay comprised a nylon Immunodyne ABC membrane spotted with anti-mouse antibodies, a plastic snap-fit device, absorbent cotton wool, mouse anti-AFM1 monoclonal antibodies (Mab), and AFB1-horseradish peroxidase (HRP) conjugate. This assay was coupled to an immunoaffinity column (IAC). The visual detection limit was 0.05 ng/g AFM1 in milk. Assay time for IAC clean-up was 12 min, and that for the flow-through assay was 18 min, hence the total assay time was 30 min. This method allows for a rapid screening of milk consignments which do not conform to the maximum permissible limits of 0.05 ng/g AFM1, hence enabling the rejection of such at the farm level. Laboratory validation was done using certified reference materials (CRM) with AFM1 concentrations of < 0.05, 0.09 and 0.76 ng/g. Precision of the assay was high as shown by the high repeatability of the assay results. There were no significant differences in recoveries between standard in buffer and CRM (P > 0.05), and assay responses for these two were highly correlated (99.63%).
authors.affiliation: Laboratory of Food Analysis, Faculty of Pharmaceutical Sciences, University of Gent, Belgium. liberty.sibanda@rug.ac.be
authors.forename: L
authors.initials: L
authors.lastname: Sibanda
authors.forename: S
authors.initials: S
authors.lastname: De Saeger
authors.forename: C
authors.initials: C
authors.lastname: Van Peteghem
mesh_terms: D016607:Aflatoxin M1 / Q000032:analysis*; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D051379:Mice; D008892:Milk / Q000737:chemistry*; D011817:Rabbits
chemical_list: D016607:Aflatoxin M1