Search

Abstract: Fumonisin B1 (FB1) is a mycotoxin, mainly produced by Fusarium fungi and present in food and feed. It causes harmful effects on human and animal health. Therefore, it is necessary to develop sensitive and reliable screening methods. In this study, a highly sensitive monoclonal antibody (MAb) against FB1, clone 2D7, was produced, and the 50% inhibition concentration (IC50) of the MAb was 2.2 ng/mL in buffer. The MAb showed high cross-reactivity with fumonisin B2 (FB2), and negligible cross-reactivity with other mycotoxins. A sensitive indirect competitive enzyme-linked immunosorbent assay (icELISA) based on this MAb was developed for the determination of FB1 in maize. In spiked samples (100, 200 and 500 μg/kg), the average recoveries ranged from 78 ± 11 to 107 ± 4%, and the coefficient of variation ranged from 3 to 15%. The limit of detection of the icELISA was 5.4 μg/kg. This method was compared to liquid chromatography tandem mass spectrometry (LC–MS/MS) using naturally contaminated samples, and the correlation coefficient was above 0.82. These results show the reliability of the icELISA method for the determination of FB1 in maize. [Copyright &y& Elsevier]

Abstract: A sensitive and specific enzyme-linked immunosorbent assay (ELISA) for the detection of 1-amino-hydantoin (AHD) is described. AHD, the marker residue for nitrofurantoin, is a tissue bound toxic metabolite. To monitor the illegal use of nitrofurantoin, a monoclonal antibody-based ELISA method was developed to detect AHD residue in animal tissues. The highly specific antibody against AHD was prepared by monoclonal antibody technology. The antibody exhibited negligible cross reactivity with other nitrofurans, their metabolites and derivatives, and 50% inhibitory concentration was 0.68 μg/L. The limit of detection in four kinds of animal tissues were all below 0.2 μg/kg and recoveries ranged from 75% to 116.7% for fortified samples at levels of 0.2–5 μg/kg with coefficient of variation values below 15%. Analysis of natural contaminated samples by the ELISA method gave similar results to those of the liquid chromatography-tandem mass spectrometry method. These results indicate the ELISA method is suitable for the detection of AHD residue in animal tissues. [Copyright &y& Elsevier]

The flunixin residues in foods of animal origin could pose hazards for human health. In this paper, a broad-selectivity polyclonal antibody was obtained using 5-hydroxyflunixin coupled with bovine serum albumin as the immunogen. The semi-inhibitory concentration (IC50) of the polyclonal antibody was 1.43 ng/mL for flunixin and 0.29 ng/mL for 5-hydroxyflunixin, respectively, which were far below the maximum residue limits set by the United States, the European Union and China. The limits of detection were calculated to be 2.98 μg/kg for flunixin in bovine muscle and 0.78 μg/L for 5-hydroxyflunixin in milk. In spike and recovery tests, the average recovery ranged from 83% to 105%, with a satisfying coefficient of variance ranging from 5.8% to 11.3%. Furthermore, the ELISA method was validated by a well-established LC-MS/MS method. These results proved that the established method is suitable for flunixin and 5-hydroxyflunixin residue analysis. [ABSTRACT FROM AUTHOR]

In this study, new clindamycin (CLIN) artificial antigens were prepared and used to produce broad-specificity monoclonal antibodies. Based on the as-produced mAbs, a heterologous ELISA was developed to detect CLIN and lincomycin (LIN) residues in edible animal tissues. The IC 50 values of the developed assay were 0.3 ng/mL (CLIN) and 1.2 ng/mL (LIN) in buffer, respectively. The detection limits were estimated to be 1.8 μg/kg (CLIN) and 6.8 μg/kg (LIN) in bovine, chicken, porcine and fish muscles. In the spike and recovery tests, the mean recovery rate ranged from 76% to 112% at different spiked levels, and the intra −/inter-assay coefficients of variation were in the range of 7.1% to 13.2%. This method was verified using LC − MS/MS with a correlation coefficient > 0.97. The developed ELISA is therefore well suited for simultaneous determination of CLIN and LIN residues in bovine, chicken, porcine and fish muscles. [ABSTRACT FROM AUTHOR]

A sensitive and specific monoclonal antibody against clindamycin (CLIN) was produced and used to develop an immuno-affinity test column (IATC) assay for on-site screening of CLIN residues in milk. The qualitative limit of detection of the IATC assay, estimated as 1.0 μg L −1 by visual detection, was sufficient to measure maximum residue levels for lincosamide antibiotics in milk. The quantitative IATC assay resulted in a lower detection limit (0.11 μg L −1 ) by evaluating the colour intensity of the test layers, which was approximately 9 times greater sensitivity than visual detection. During the spike and recovery test, the average recoveries ranged from 76% to 114% at different spiked levels, and the intra-/interday coefficients of variation were in the range 9.6–16.7%. The detection time was shortened to 20 min, whereas the sensitivity was comparable with a traditional ELISA. The IATC assay shows promise for on-site screening of CLIN residues in milk. [ABSTRACT FROM AUTHOR]

Methyl-3-quinoxaline-2-carboxylic acid (MQCA) is a possible residue marker for three quinoxaline veterinary medicines (olaquindox, mequindox, and quinocetone). The wide application of mequindox/quinocetone or the illegal use of olaquindox leads to MQCA residue in animal's original food, thereby threatening the safety of human food. The indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) with a specific coating antigen and monoclonal antibody (MAB) was established and optimized for detecting MQCA in swine liver. Samples were acidified with 2 mol l hydrochloric acid, extracted with ethyl acetate-hexane-isopropanol (8 + 1 + 1, v/ v/ v) and then detected by IC-ELISA. The logarithm correlation of standards to OD values ranged from 0.2 to 200 μg l, with IC of 6.46 μg l. Negligible cross-reactivity happened to five quinoxaline antibiotics (olaquindox, mequindox, quinocetone, carbadox, and cyadox) and the metabolite of carbadox and cyadox (quinoxaline-2-carboxylic acid). When spiked with 1 to 100 μg kg of MQCA, the recoveries ranged from 85.44 to 100.02 %, with the intra-assay coefficient of variation (CV) of 6.64-10.57 % and inter-assay CV of 7.29-10.88 %. The limit of detection for MQCA was 1.0 μg kg in swine liver. Furthermore, incurred samples were detected by the IC-ELISA and then conformed by a reported LC/MS/MS method, it shown that there was good correlation between the two methods. All these results indicated that the IC-ELISA method is appropriate for surveillance MQCA residue in animal tissues. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]