应用单管半巢式PCR技术筛查转基因食品

Screening of Genetically Modified Foods by Single-Tube Semi-Nested PCR

建立转基因作物中常见的两种外源调控元件的单管半巢式聚合酶链式反应(polymerase chain reaction,PCR)检测方法,为转基因食品的筛选检测提供一种快速、精确的方法。针对6种转基因作物中Ca MV35S启动子和NOS终止子的一致性核苷酸序列,分别设计巢式PCR的内、外引物,在测试不同引物组合的扩增效率基础上,建立Ca MV35S启动子和NOS终止子的单管半巢式PCR方法。结果表明,上述方法对两种转基因成分具有良好的特异性,检测灵敏度分别为0.01%和0.05%,显著优于常规PCR方法。该方法具有便捷、准确、灵敏等特点,适合筛查食品中的转基因成分。

A single-tube semi-nested PCR method for common exogenous regulatory elements of transgenic crops was established to provide a fast and accurate assay for screening genetically modified foods. Two sets of element-specific nested PCR primers were designed based on the consensus sequence of the exogenous elements in six different transgenic crops, respectively. A single-tube semi-nested PCR assay for Ca MV35 S promoter and NOS terminator was developed by testing the amplification efficiency of different combinations of primers. This assay has been successfully applied to distinguish GM crops with Ca MV35 S promoter or NOS terminator from others with high specificity. Sensitivity tests showed that the relative limit of detection for Ca MV35 S promoter and NOS terminator were 0.01% and 0.05%, respectively, significantly better than those of conventional PCR. Consequently, the single-tube semi-nested PCR assay is convenient, accurate, sensitive and suitable for screening genetically modified foods.