Hapten Synthesis and Monoclonal Antibody Preparation for Simultaneous Detection of Albendazole and Its Metabolites in Animal-Origin Food

Albendazole (ABZ) is one of the benzimidazole anthelmintics, and the overuse of ABZ in breeding industry can lead to drug resistance and a variety of toxic effects in humans. Since the residue markers of ABZ are the sum of ABZ and three metabolites (collectively referred to as ABZs), albendazole-sulfone (ABZSO2), albendazole-sulfoxide (ABZSO), and albendazole-2-amino-sulfone (ABZNH2SO2), an antibody able to simultaneously recognize ABZs with high affinity is in urgent need to develop immunoassay for screening purpose. In this work, an unreported hapten, 5-(propylthio)-1H-benzo[d]imidazol-2-amine, was designed and synthesized, which maximally exposed the characteristic sulfanyl group of ABZ to the animal immune system to induce expected antibody. One monoclonal antibody (Mab) that can simultaneously detect ABZs was obtained with IC50 values of 0.20, 0.26, 0.77, and 10.5 μg/L for ABZ, ABZSO2, ABZSO, and ABZNH2SO2 in ic-ELISA under optimized conditions respectively, which has been never achieved in previous reports. For insight into the recognition profiles of the Mab, we used computational chemistry method to parameterize cross-reactive molecules in aspects of conformation, electrostatic fields, and hydrophobicity, revealing that the hydrophobicity and conformation of characteristic group of molecules might be the key factors that together influence antibody recognition with analytes. Furthermore, the practicability of the developed ic-ELISA was verified by detecting ABZs in spiked milk, beef, and liver samples with recoveries of 60% to 108.8% and coefficient of variation (CV) of 1.0% to 15.9%.

Design of Hapten Synthesis and Antibody Characterization of G-group Aflatoxins

Food and feed contamination with Aflatoxins pose a serious threat to human health and animal husbandry development and has caused widespread concern, among them, G-group Aflatoxins as the main pollutant has attracted more and more attention. In order to establish a rapid, sensitive, specific and efficient immunoassay method for G-group aflatoxins, this study aimed to designed to synthesize 3 immunogens and coating antigens and identified by UV and SDS-PAGE. Then used to immunize Balb/c mice with prepared of three immunogen the titers were determined by indirect ELISA and the sensitivity was determined by competitive indirect ELISA (icELISA), the specificity was assessed by the cross-reaction test (CR). The results of UV and SDS-PAGE showed that the three immunogens and the corresponding coated antigens were successfully synthesized and the best one was SA method among three synthesis methods of G-group AF artificial antigen and its conjugation ratio of AFG1 to BSA was about 5.64∶1. The immune efficacy of SA method was the best, its AFG1 pAb had high titers of 1∶(6.4×103) by indirect ELISA, a good sensitivity with the 50 % inhibition concentration(IC50) of 13.6 μg/kg－1 to AFG1 by blocking ELISA and a high CR to AFG2 of 82.19 %, it showed high specificity for other aflatoxins. The experimental results not only obtained the ideal G group aflatoxin antibody, but also established a substance and technology foundation for G group aflatoxin immunization methods, and can be referenced in the similar tests.

Hapten synthesis and antibody production for the development of a paper immunosensor for lean meat powder zilpaterol

An anti-zilpaterol mAb with an IC50 of 0.31 ng mL−1 and a limit of detection (LOD) of 0.02 ng mL−1 has been developed. For semi-quantitative detection in pork samples, the visual LOD is 0.5 ng mL−1 and the cut-off value is 5 ng mL−1.

Monoclonal antibodies with subnanomolar affinity to tenofovir for monitoring adherence to antiretroviral therapies: from hapten synthesis to prototype development

High-affinity antibodies were generated to develop enzymatic and lateral flow immunoassays for monitoring tenofovir, a drug commonly used for treating HIV infection and used as a biomarker of adherence to the therapy.