Establishment and Application of an Immunomagnetic Bead-based MELISA Method for Olaquindox

Abstract:

[Objective] This study aims to establish a magnetic bead enzyme-linked immunosorbent assay (MELISA) method for olaquindox (OLA) based on immunomagnetic beads.[Method] First, olaquindox-hapten conjugated with horseradish peroxidase (OLA-HS-HRP) and immunomagnetic beads were synthesized. Then, the conjugated immunomagnetic beads and OLA-HS-HRP were used to screen and optimize the reaction conditions of MELISA.[Result] The optimal working dilution factors for the immunomagnetic beads and OLA-HS-HRP were 100 times and 8 000 times, respectively, with the antibody dilution buffer being PBS solution (0.010 mol/L, pH 7.0) containing methanol at a volume fraction of 5%. Under the optimized conditions, the established standard equation was y=13.593ln x+17.173 (R²=0.994 3), with IC₁₀, IC₂₀, IC₅₀, and IC₈₀ values of 0.59, 1.23, 11.19, and 101.70 ng/mL, respectively. The recovery rate of this method was 93.17%~106.83%, and the coefficient of variation (CV) was <7%.[Conclusion]The MELISA established in this study is highly sensitive and reliable, providing a new method for the detection of OLA residues and offering a theoretical basis and reference for the detection of other small molecule drugs in food safety.