Research on the direct competition ELISA analysis ofβ-lactamase inhibitor-sulbactam in milk

The aim of this study was to establish a direct competitive enzyme-linked immunoassay ( dc-ELISA) method to detect the representative β-lactamase inhibitor-sulbactam in dairy products.After analyzing the condition of blocking solution concentration, ion concentration, coating conditions, p H, and other optimization, this developed method presented an IC₅₀ of5.25 ng/m L, a detection limit IC₁₅ of 1.07 × 10^-3ng/m L. Intra-and inter-batch relative standard deviations ( RSD) were6.69%, 9.02%, respectively.The cross-reactivity rates for tazobactam and clavulanic acid were 7.12%, 0.93%, respectively.The recoveries of milk in spiked samples ranged from 85.66% ~89.23%. The developed dc ELISA method was satisfied for the the field of mass rapid screen of sulbactam residue in milk samples.