A highly sensitive monoclonal antibody−based paper sensor for simultaneously detecting valnemulin and tiamulin in porcine liver

Abstract

Valnemulin (VAL) and tiamulin (TIA) are pleuromutilin antibiotics used primarily for treating bacterial infections in swine or other food animals. Furthermore, VAL and TIA are also employed as feed additives to promote animal growth. However, the illegal use of VAL and TIA could cause a series of hazards to consumers. Here, VAL was designed to be conjugated with bovine serum protein to prepare immunogen. A highly sensitive monoclonal antibody that recognized both VAL and TIA has been successfully produced. Moreover, an immunochromatographic strip assay for rapidly screening VAL and TIA in porcine liver was established with visual detection limits (cutoff values) of 50 and 25 ng/g, respectively. The IC50 values calculated from the equation of the standard curve were 6.06 and 3.45 ng/g and the limits of detection were 0.96 and 0.29 ng/g for VAL and TIA. According to the recovery experiment results, the test strip exhibited acceptable accuracy and precision. Generally, the proposed strip provided a practical tool for the detection of VAL and TIA. Practical Application We produced a highly sensitive monoclonal antibody and developed an immunoassay strip for simultaneously monitoring TIA and VAL. Additionally it was preliminarily confirmed that the rapid detection tool was suitable for screening TIA and VAL in porcine liver.

Quantum dots‐based fluorescence immunoassay for detection of tiamulin in pork

“…At the same time, icFLISA has no enzymatic reaction steps and saves washing times, which was more convenient than icELISA. Moreover, Lei et al (2018) and Na et al (2020) reported previously used monoclonal antibodies to establish icELISA for detection of TML, with IC 50 values of 0.36 ng/ml and 0.392 ng/ml, respectively. The results indicated that icFLISA based on QDs was more sensitive than traditional icELISA for TML detection.…”

“…The procedure of icELISA was similar to a previously described method (Chen et al, 2020; Lei et al, 2018; Na et al, 2020). The transparent polystyrene 96‐well microtiter plates were coated with 100 μl TML‐OVA, which diluted with CBS buffer and incubate at 37°C for 2 hr.…”

“…The pork samples were purchased from a local supermarket and pretreated by methanol extraction method (Na et al, 2020). First, 2 g pork samples were vacuum freeze‐dried into powder and moved into a centrifuge tube.…”

Sensitive Lateral Flow Immunoassay for the Residues of Imidocarb in Milk and Beef Samples

“…Then, the activated mixture was added dropwise to a protein solution (6 mg of BSA was dissolved in 2 mL carbonate–bicarbonate buffer, pH 9.6) with stirring overnight at 4 °C. Lastly, the resulting conjugate hapten A–BSA was dialyzed with PBS for 2–3 days and then stored at −20 °C for future use. − …”

Detection of quinocetone in animal feed by quantum dots‐based indirect competitive fluorescent immunosorbent assay

“…The process of ic-ELISA was analogous to a previously reported method (Na et al, 2020). The QCT-OVA was diluted to optimal concentration by CBS buffer and coated on a 96-well plate with 100 μl/ well.…”