Visual detection of donkey-derived ingredients by loop-mediated isothermal amplification with 4-(2-pyridylazo)-resorcinol sodium salt

Abstract

The objective of this study was to develop a reliable visual method for rapid detection of donkey components to protect consumers from commercial adulteration. Six specific loop-mediated isothermal amplification (LAMP) primers targeted at donkey mitochondrial cytochrome b gene were designed, the mitochondrial DNA extraction simplified, the LAMP reaction system optimized, the specificity verified with mitochondrial DNA of horse, pork, cow, sheep, chicken, duck, and rabbit as negative controls, the detection limit determined with gradient dilution of adulterated meat with donkey meat, and the visual LAMP method for detection of donkey-derived ingredient in common meat products established. The results showed that the modified mitochondrial DNA extraction method was simple and repeatable, and the visual LAMP method with 4-(2-pyridylazo)-resorcinol sodium salt as indicator can accurately and specifically detect the donkey meat in common meat products, 1% detection limit. The study provided a promising solution for facilitating the surveillance of the commercial adulteration in processed meat.