A novel hapten and monoclonal-based enzyme-linked immunosorbent assay for 3-methyl-quinoxaline-2-carboxylic acid in edible animal tissues

Abstract

To monitor the illegal use of olaquindox (OLA) in animals, a novel hapten and monoclonal antibody for 3-methyl-quinoxaline-2-carboxylic acid (MQCA), the marker residue for OLA, had been produced. And then, the monoclonal-based indirect competitive enzyme linked immunosorbent assay (ic-ELISA) has been established with simple sample preparation and clean-up. The obtained antibody 5B10 that has isotype IgG1 showed an IC₅₀ value of 17.7 μg L⁻¹ for MQCA and did not exhibit measurable cross-reactivity with other antibiotics. The limits of detection ranged from 1.9 μg kg⁻¹ to 4.3 μg kg⁻¹. The recoveries were from 74.2% to 98.9% with a maximum coefficient of variation of 17.3%. A good correlation between ELISA and HPLC results of the incurred tissues demonstrated the reliability of the developed ic-ELISA. It would be a useful tool for the screening of the residues of MQCA in the edible tissues of animals.