目的制备用于检测肉制品中沙门菌实时荧光定量聚合酶链反应(PCR)的标准质粒。方法设计针对沙门菌inv A基因的引物,扩增特异片段,转入质粒载体中构建重组质粒。将构建的重组质粒作为标准品,进行优化后的实时荧光定量PCR,建立标准曲线,并考察该标准品灵敏性及稳定性。结果成功构建含有沙门菌inv A基因的质粒标准品,用其建立的标准曲线循环阈值(Ct值)与模板的拷贝数呈良好线性关系(r2=0.9979),最低可以检出10拷贝/反应。该标准质粒经验证具有良好的稳定性。用该质粒标准品检测肉制品中的沙门菌,经2 h增菌后,可在7 h内完成对样品的检测。结论所构建的质粒标准品可用于荧光定量PCR检测肉制品中的沙门菌,为考量实验质量提供参考依据。 Objective To prepare a standard plasmid for the detection of Salmonella in real-time fluorescent quantitative polymerase chain reaction (PCR) in meat products. Methods Primers designed for the invA gene of Salmonella were designed and amplified into specific plasmids for construction of recombinant plasmids. The constructed recombinant plasmid was used as a standard sample, and the optimized real-time fluorescence quantitative PCR was performed to establish a standard curve. The sensitivity and stability of the standard were also investigated. Results The plasmid standard containing the invA gene of Salmonella was successfully constructed. The standard curve established by this method showed a good linearity (r2 = 0.9979) between the standard curve of Ct value and the copy number of the template, and the lowest copy number of 10 copies / reaction was obtained. The standard plasmid has been verified to have good stability. Salmonella in meat products was detected with this plasmid standard. After 2 hours of enrichment, the detection of the samples could be completed within 7 h. Conclusion The constructed plasmid standard can be used to detect Salmonella in meat products by fluorescence quantitative PCR, which can provide reference for the quality of experiment.