Development of a monoclonal antibody for the detection of xylazine in milk and its use in an immunochromatographic strip
Abstract
We prepared a monoclonal antibody (mAb) which was sensitive and specific against xylazine based on a new hapten. The 50%-inhibitory concentration (IC50) of the mAb against xylazine was 0.399 ng mLâ1 and the mAb was of the IgG2b subclass. A cross-reactivity test showed that the mAb had very high specificity for xylazine. An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and gold nanoparticle-based lateral-flow test (GNT) strip were developed for the rapid screening of xylazine in milk samples. The limit of detection (LOD) and cut-off value of the GNT assay were evaluated to be 20 and 200 ng mLâ1 in milk samples with the naked eye. The average recoveries of xylazine which was detected by the ic-ELISA ranged from 95.1% to 105.1%. Real samples were used to confirm the accuracy of the developed GNT strip. These results demonstrated that we had developed a very reliable method for rapid detection of xylazine in milk samples.