Comparison of Some ELISA Kits for Aflatoxin M1 Quantification

Background: ELISA is a widely used method for aflatoxin M1 (AFM1) quantification in dairy products. This study was conducted to compare ELISA kits from different manufacturers for AFM1 quantification inmilk. Methods: High sensitivity ELISA kits (for up to 250 ng AFM1/L), including AgraQuant (Romer Labs), Bioshield M1ES (Prognosis Biotech), Helica 96 (Helica Biosystems), Veratox (Neogen, Inc.), and the medium sensitivity kit Immunolab AM1E01 (Immunolab GmbH; for 10–1000ng AFM1/L) were tested against a certified reference AFM1 whole milk having 44 ng AFM1/L and its 10-fold dilution, and a50 ng AFM1/L standard. In another experiment, Prognosis Bioshield M1UF (70–1000 ng AFM1/L), Romer’s AgraquantPlus (10–2000 ng AFM1/L), and Immunulab’s AM1E01 kits were compared totest a 500 ng AFM1/L solution. Results: In both of the experiments, the quantification ofthe tested AFM1 levels did not differ (P ≥ 0.310) between the kitsfrom various manufacturers. In the case of 4.4 ng AFM1/L, recovery of the toxin wasclose to the assigned value under the kit by Neogen, Inc. Incase the of 44 ng level, better recoveries were seen under the kits by Immunolab and Prognosis Biotech. In both the cases, low relative standard deviation (RSD) values were obtained only for the kit by Prognosis Biotech. In the case of the 50 and 500 ng AFM1/L solutions, the kits by Prognosis Biotech and Romer Labs provided recoveries close tothe assigned values as well as low RSD. Conclusions: These data indicate that all thestudied ELISA kit brands had comparable efficacy forAFM1 quantification. Recovery of the toxin and RSD may, however, differ between kits fromvarious manufacturers.