复合调味料食用方便、口味多样,具有巨大的市场发展潜力,但相关食品安全问题也时有发生。该研究建立了实时荧光跨越式滚环等温扩增(real-time fluorescence-saltatory rolling circle amplification,RF-SRCA)熔解曲线法检测复合调味料...复合调味料食用方便、口味多样,具有巨大的市场发展潜力,但相关食品安全问题也时有发生。该研究建立了实时荧光跨越式滚环等温扩增(real-time fluorescence-saltatory rolling circle amplification,RF-SRCA)熔解曲线法检测复合调味料中沙门氏菌的方法。RF-SRCA反应完成后,通过熔解曲线法检测沙门氏菌,可排除引物二聚体或非特异产物对检测结果的影响,准确直观地判定检测结果。进行引物特异性验证,并对灵敏度和人工污染样品的检出限进行分析。结果表明,该方法能有效检测沙门氏菌,14株沙门氏菌均为阳性结果,熔解峰形一致,且Tm值范围稳定,25株非沙门氏菌均为阴性结果。RF-SRCA熔解曲线方法的灵敏度为6 fg/μL,较实时荧光PCR(real-time fluorescence-PCR,RF-PCR)灵敏度高出100倍。检出限为4.6×10^(0) CFU/g,比RF-PCR低100倍。与RF-PCR方法相比,RF-SRCA检测方法灵敏度更高,检出限更低。因此,该研究建立的RF-SRCA熔解曲线方法可对复合调味料中沙门氏菌实现快速、准确、特异、灵敏的检测。展开更多
Here we report the construction of sheep PrP gene standard plasmid DNA and curve using real-time RT-PCR.Total RNA was extracted from each sample and the fragments of target gene were amplified by RT-PCR.The plasmid wa...Here we report the construction of sheep PrP gene standard plasmid DNA and curve using real-time RT-PCR.Total RNA was extracted from each sample and the fragments of target gene were amplified by RT-PCR.The plasmid was constructed for calibrating unknown samples.In this study,the constructed plasmid containing only the target gene was used to construct a calibration curve.The absolute standard curve method was shown to be of high linearity,sensitivity and reproducibility.The purpose of this study is to investigate the quantification of PrP mRNA expression for knowing the scrapie pathogenesis and providing powerful tool for further studies on prion diseases pathogenesis.展开更多
为定量测定瘤胃脂肪分解菌,试验构建了脂肪分解菌实时荧光定量PCR的标准品及标准曲线。提取瘤胃微生物总DNA,以脂肪分解菌16S r DNA特异性引物进行PCR扩增,回收PCR产物,与PMD19-T Vector连接并转化大肠杆菌。阳性重组质粒经PCR和测序鉴...为定量测定瘤胃脂肪分解菌,试验构建了脂肪分解菌实时荧光定量PCR的标准品及标准曲线。提取瘤胃微生物总DNA,以脂肪分解菌16S r DNA特异性引物进行PCR扩增,回收PCR产物,与PMD19-T Vector连接并转化大肠杆菌。阳性重组质粒经PCR和测序鉴定后,将提取的质粒DNA进行梯度稀释并作为模板,利用荧光定量PCR反应做出标准曲线。结果显示:PCR产物与目的基因的相似性大于99%,以不同稀释度的重组质粒为模板获得的荧光定量PCR扩增曲线差异明显,构建了相关系数接近1的标准曲线,且熔解曲线峰值单一。试验建立的实时荧光定量PCR方法可用于瘤胃脂肪分解菌的定量检测,为进一步研究该菌在反刍动物瘤胃发酵中的分子机理奠定了基础。展开更多
文摘复合调味料食用方便、口味多样,具有巨大的市场发展潜力,但相关食品安全问题也时有发生。该研究建立了实时荧光跨越式滚环等温扩增(real-time fluorescence-saltatory rolling circle amplification,RF-SRCA)熔解曲线法检测复合调味料中沙门氏菌的方法。RF-SRCA反应完成后,通过熔解曲线法检测沙门氏菌,可排除引物二聚体或非特异产物对检测结果的影响,准确直观地判定检测结果。进行引物特异性验证,并对灵敏度和人工污染样品的检出限进行分析。结果表明,该方法能有效检测沙门氏菌,14株沙门氏菌均为阳性结果,熔解峰形一致,且Tm值范围稳定,25株非沙门氏菌均为阴性结果。RF-SRCA熔解曲线方法的灵敏度为6 fg/μL,较实时荧光PCR(real-time fluorescence-PCR,RF-PCR)灵敏度高出100倍。检出限为4.6×10^(0) CFU/g,比RF-PCR低100倍。与RF-PCR方法相比,RF-SRCA检测方法灵敏度更高,检出限更低。因此,该研究建立的RF-SRCA熔解曲线方法可对复合调味料中沙门氏菌实现快速、准确、特异、灵敏的检测。
文摘Here we report the construction of sheep PrP gene standard plasmid DNA and curve using real-time RT-PCR.Total RNA was extracted from each sample and the fragments of target gene were amplified by RT-PCR.The plasmid was constructed for calibrating unknown samples.In this study,the constructed plasmid containing only the target gene was used to construct a calibration curve.The absolute standard curve method was shown to be of high linearity,sensitivity and reproducibility.The purpose of this study is to investigate the quantification of PrP mRNA expression for knowing the scrapie pathogenesis and providing powerful tool for further studies on prion diseases pathogenesis.
文摘为定量测定瘤胃脂肪分解菌,试验构建了脂肪分解菌实时荧光定量PCR的标准品及标准曲线。提取瘤胃微生物总DNA,以脂肪分解菌16S r DNA特异性引物进行PCR扩增,回收PCR产物,与PMD19-T Vector连接并转化大肠杆菌。阳性重组质粒经PCR和测序鉴定后,将提取的质粒DNA进行梯度稀释并作为模板,利用荧光定量PCR反应做出标准曲线。结果显示:PCR产物与目的基因的相似性大于99%,以不同稀释度的重组质粒为模板获得的荧光定量PCR扩增曲线差异明显,构建了相关系数接近1的标准曲线,且熔解曲线峰值单一。试验建立的实时荧光定量PCR方法可用于瘤胃脂肪分解菌的定量检测,为进一步研究该菌在反刍动物瘤胃发酵中的分子机理奠定了基础。
