Development of a highly sensitive monoclonal antibody-based indirect competitive enzyme-linked immunosorbent assay for the detection of avilamycin in feed

An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was developed using a highly sensitive and specific monoclonal antibody against avilamycin. The immunising antigen synthesised through the carbonyldiimidazole (CDI) method was used to prepare antibodies. The established ic-ELISA, after optimisation of conditions, possessed a half maximum inhibitory concentration (IC50) value of 7.44 ng mL-1 and the detection limit of 0.21 ng mL(-1) in the standard curve. The spiked experiments indicated that the limits of detection were 1.86 mu g kg(-1) and 2.31 mu g kg(-1) in swine feed and chicken feed, respectively. In addition, the average recoveries ranged from 74.7 to 105.4% with the coefficient of variation less than 11%. The good correlation (R-2 = 0.9818) between the result of ic-ELISA and HPLC demonstrated the reliability of the developed ic-ELISA, which showed that the ic-ELISA developed here achieves the aim of strengthening the monitoring of avilamycin residues and the inspection of import and export related products.

Automated summary

An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) using a highly sensitive and specific monoclonal antibody against avilamycin was developed. The optimized ic-ELISA showed low detection limits and good correlation and reliability compared to HPLC.