Immunochromatographic assay based on high‐affine monoclonal antibody for the detection of imidocarb in milk

Abstract

Imidocarb (IM) is an antiprotozoal agent, which is mainly used to treat babesiosis and piroplasmosis for animals. However, overdose or improbable utilization cause IM residues in animal origin products, which would be harmful to human health. Here, a monoclonal antibody (mAb) against IM with extremely sensitive and specific features has been successfully prepared from a novel immunogen synthesized by virtue of the active ester method. The concentration of half-maximal inhibition (IC 50 ) of the mAb was 0.074 ng/ml and the affinity constant was 4.58 × 10 10 L/mol. On the basis of this condition, an immunochromatographic strip (ICS) is proposed that could be applied in milk samples to test IM rapidly. For the ICS, the visual detection limit (cut-off value) was 5 ng/ml, IC 50 was 0.4 ng/ml, the limit of detection (LOD) was 0.078 ng/ml, the linear detection scope was 0.117 to 1.37 ng/ml. The recovery rates ranged from 88.83% to 91.47% and coefficients of variation (CV) were in the spectrum of 7.31% to 9.43%. In general, the recommended test strip provided an exceedingly simple and reliable detection method for quickly testing the IM. Practical Application: In our joint efforts, an extremely sensitive monoclonal antibody against imidocarb was obtained and a test strip for the rapid detection of imidocarb in milk was developed. The developed method could be applied to the field and provided great potential for analytical of imidocarb in other matrixes.

Quantum dot‐based fluorescence immunosorbent assay for the rapid detection of bacitracin zinc in feed samples

“…BAC‐BSA and BAC‐OVA complete antigens were prepared using the EDC/NHS method. [ 24,25 ] First, 10 mg of BSA was dissolved in 2‐(4‐morpholino)ethanesulfonic acid (MES; pH 5.5, 0.1 mol/L) buffer. Next, EDC (5.5 mg) and NHS (4 mg) were added to the above solution and stirred for 30 min.…”

“…BAC-BSA and BAC-OVA complete antigens were prepared using the EDC/NHS method. [24,25] First, 10 mg of BSA was dissolved in Then, at 14-day intervals, the mice were immunized with three booster immunizations with the same dosage of immunogen but using Freund's incomplete adjuvant. Indirect competitive ELISA (ic-ELISA)…”