Highly broad-specific and sensitive direct competitive enzyme-linked immunosorbent assay for screening multi-antibacterial synergists: assay optimization and application to animal-derived food

摘要

The optimum conditions of a direct competitive enzyme-linkedimmunosorbent assay (dcELISA) in regard to different monoclonalantibodies (MAbs), coating conditions, blocking conditions andphysicochemical factors of the assay buffer were investigated todevelop a broad-specific and sensitive immunoassay for detectionof antibacterial synergists (ASGs) in milk, eggs, chicken and pork.Under optimized conditions, a highly broad-specific and sensitivedcELISA for ASGs was obtained based on 5C4 and hapten-C-HRP,demonstrating a 50% specific binding (IC 50 ) for five ASGs of0.208–9.24 ng mL ?1 with cross-reactivity (CR) of 138.2–7.5%. Theoptimized dcELISA was used to quantify the five ASGs in milk,egg, chicken muscle and beef with the average recoveries of79.5–105.4% and coefficients of variation (CV) less than 13.4%. Theestablished method with broad specificity and uniform affinity,offered a simple, sensitive, and high-throughput screening tool forthe detection of multi- ASGs in animal-derived food.