highly specific anti-tylosin monoclonal antibody and its application in the quantum dot bead-based immunochromatographic assay

In this study, mab-5a7 and mab-1d7, two highly specific monoclonal antibodies against tylosin (tyl), were prepared by using hapten tyl-carboxymethoxylamine hemihydrochloride (tyl-cmo), and they showed ic50 values of 13.84 ng/ml and 13.01 ng/ml and lods of 1.21 and 0.98 ng/ml, respectively, in indirect competitive enzyme-linked immunosorbent assay. an immunochromatographic assay based on quantum dot (qd)-embedded nanobead (qb-ica) and mab-1d7 was developed for the detection of tyl in milk and honey. the ic50 values of qb-ica in pbs, milk, and honey were calculated to be 22.4, 18.5, and 24.41 ng/ml, with lods of 2.32, 1.84, and 2.69 ng/ml, respectively, satisfying the requirement of the maximum residue limit for tyl in food samples of 100–300 μg/kg in china. the cross-reactivity (cr) values with two related compounds, tilmicosin and abamectin, were 4.48% and 1.87%, respectively, and the cr values with other drugs were all less than 0.2%, which indicated that the developed qb-ica was highly specific for the determination of tyl. in addition, recovery experiments indicated that the recoveries ranged from 92.16 to 108.5% in milk and from 84.12 to 110.5% in honey. therefore, the developed qb-ica is reliable for determining tyl in milk and honey. in conclusion, the qb-ica we developed can be considered an effective and rapid tool for screening tyl in food products.