Comparison of Some ELISA Kits for Aflatoxin M 1 Quantification.

Background: ELISA is a widely used method for aflatoxin M ₁ (AFM ₁ ) quantification in dairy products. This study was conducted to compare ELISA kits from different manufacturers for AFM ₁ quantification in milk. Methods: High sensitivity ELISA kits (for up to 250 ng AFM ₁ /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 10-1000 ng AFM ₁ /L) were tested against a certified reference AFM ₁ whole milk having 44 ng AFM ₁ /L and its 10-fold dilution, and a 50 ng AFM ₁ /L standard. In another experiment, Prognosis Bioshield M1UF (70-1000 ng AFM ₁ /L), Romer's AgraquantPlus (10-2000 ng AFM ₁ /L), and Immunulab's AM1E01 kits were compared to test a 500 ng AFM ₁ /L solution. Results: In both of the experiments, the quantification of the tested AFM ₁ levels did not differ ( P ≥ 0.310) between the kits from various manufacturers. In the case of 4.4 ng AFM ₁ /L, recovery of the toxin was close to the assigned value under the kit by Neogen, Inc. In case 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 AFM ₁ /L solutions, the kits by Prognosis Biotech and Romer Labs provided recoveries close to the assigned values as well as low RSD. Conclusions: These data indicate that all the studied ELISA kit brands had comparable efficacy for AFM ₁ quantification. Recovery of the toxin and RSD may, however, differ between kits from various manufacturers.