Development of an immunomagnetic bead clean-up ELISA method for detection of Maduramicin using single-chain antibody in chicken muscle

Abstract

ABSTRACTAn indirect competitive enzyme-linked immunosorbent assay (icELISA) based on immunomagnetic bead clean-up for detection of Maduramicin (MAD) was developed using a single-chain antibody (scFv). The single-chain antibody synthesized by genetic engineering technology was immobilized on the surface of carboxylic acid magnetic beads with a diameter of 2.8 μm. After simple extraction, the residue in the sample extract was specifically adsorbed, and the supernatant was removed by magnetic separation. The half-maximal inhibitory concentration (IC50) of 15.43 ng·ml−1 with a limit of detection of 6.31 ng·ml−1 for MAD in chicken muscle. The recovery ranged from 72.93 to 89.51% with variation coefficients in intraday and interday less than 15%. We improved the inhibition efficiency and sensitivity of this method compared with traditional hydrophilic-lipophilic balance column clean up icELISA. The convenience and repeatability of the immunomagnetic clean-up render the new method for the analysis of drug residues in complex matrices.