转基因大豆及其制品二重荧光定量PCR的建立与验证

研究选用花椰菜花叶病毒35S启动子(P-35S)和根癌农杆菌胭脂碱合成酶基因终止子(T-NOS)为靶标基因,运用多重实时荧光PCR技术对转基因大豆及其制品进行快速筛选检测。实验通过样品核酸提取与质控,多重引物及荧光探针的设计与筛选,反应条件和反应体系的对比优化,摸索出二重荧光定量PCR检测的最佳反应体系。同时通过特异性、重复性、灵敏性和适用性实验验证,确保了该方法在同时检测2个靶标基因时,无荧光信号的相互干扰,不会出现假阴性和假阳性结果。结果表明,方法特异性高,可同时筛查两个靶标基因,扩增效率在90%~110%之间,标准曲线决定系数R2>0.98,确定了最低检测限为2拷贝/μL。开发和建立的二重荧光定量PCR检测技术可以实现一管多检的实际需要,降低试剂成本,缩短检测时间,为大豆及其深加工产品转基因成分的快速检测提供了有效方法,为促进食品进出口提供技术保障。     

四重实时荧光PCR快速检测转基因玉米及其加工产品

本研究运用四重实时荧光聚合酶链式反应技术（polymerase chain reaction,PCR）对转基因玉米及其深加工制品进行筛选检测。选定花椰菜花叶病毒35S启动子（pCaMV35S）、农杆菌的胭脂碱合成酶基因终止子（tNOS）以及根癌农杆菌CP4蛋白基因和5-莽草酸-3-磷酸合成酶基因（EPSPS）为外源基因,选定编码玉米淀粉合成酶异构体zSTSII-2 (zSSIIb) 基因作为玉米物种的内参照基因。设计和合成靶标基因特异性引物和多重荧光探针,经特异性、重复性、灵敏性和适用性等方法学验证建立了四重实时荧光PCR检测方法。结果表明该方法检测特异性强,重复性好,扩增效率在90%~110%,标准曲线相关系数R2≥0.99,最低检测限为每20 μL反应13个拷贝,最低定量限为每20 μL反应1.3个拷贝,其检测结果与SN/T 1204-2016标准方法检测结果一致,由于四个目标基因可以在一个反应管中进行扩增反应,且含有内源基因和外源基因,可降低试剂成本,简化操作程序,缩短检测时间,为玉米及其深加工产品转基因成分的快速检测提供参考。     

肉制品中植源性转基因成分多重荧光定量PCR检测方法的建立

为改善产品品质,肉制品加工过程中常常添加植物源性成分,当前转基因农作物的商品化及其在市场上 的广泛流通导致肉制品中被带入植源性转基因成分的风险增加。以转基因植物中常涉及的调控元件CaMV 35S启 动子、NOS终止子以及标记基因NPTⅡ为检测目标,设计相应的引物和Taq man探针,利用载体pRⅠ 101-AN DNA 为模板,通过优化反应体系和反应参数,建立肉制品中植源性转基因成分的单重和多重荧光定量聚合酶链式反应 （polymerase chain reaction,PCR）检测方法。通过比较分析,考察多重荧光定量PCR检测方法的灵敏性、重复性和准 确性,结果表明,多重荧光定量PCR检测方法灵敏度高、重复性好且与单重体系的检测结果具有很好的一致性。     

多重串联式PCR基因碟片技术检测转基因大豆GTS 40-3-2

建立多重串联式PCR(MT-PCR)的基因碟片技术用于转基因大豆GTS40-3-2的检测。针对GTS 40-3-2的常见外源基因NOS终止子、CP4-EPSPS、Ca MV35S启动子和大豆内源基因Lectin设计引物,同时针对外源基因插入位点的旁临序列设计品系特异性引物。首先进行一次循环数较少(15 cycles),引物浓度较低(0.1μmol/L)的高通量多重PCR,以均匀地扩增各基因模板,同时避免引物之间的竞争,然后利用巢式荧光定量PCR检测各个基因。根据熔融曲线分析结果,灵敏度高于普通荧光定量PCR法1个数量级。该方法能够快速、高通量、准确地检测转基因大豆GTS40-3-2中的多种转基因成分,并能对该品系进行分析,重复性好,适合转基因的高通量、定量检测,可用于特异性检测转基因大豆GTS40-3-2,具有较好的应用价值。     

转基因大豆DNA检测芯片的研究

为提高对转基因大豆的监督检测能力，研制了转基因大豆DNA检测芯片。根据转基因大豆(Roundup Ready)中所转入的外源基因，选择CaMV35S启动子、NOS终止子、NOSIEPSPE基因和内源Lectin基因设计特异性引物，采用多重PCR法对待测样品进行扩增，通过缺口平移法合成DIGdUTP标记杂交探针，并制备基因芯片。在对PCR反应和扩增产物与芯片杂交条件进行优化的同时，比较了芯片检测的特异性和重复性，并对检测的灵敏度进行测试。结果表明，该方法具有较好的特异性和重复性，检测灵敏度可达0．5％，由于采用了多重PCR技术，一次可同时检测多个基因，提高了检测的准确性和效率。     

实时荧光PCR方法检测转基因豆粕的研究

以美国、阿根廷和转基因大豆标准品为材料,利用设计的特异性引物和探针,建立了实时荧光定量PCR技术检测抗草甘膦转基因豆粕的方法,成功检测出美国和阿根廷抗草甘膦转基因豆粕的内源参照基因lectin、CaMV35S/CTP of EPSPS边界序列和NOS终止子,确定了实时荧光PCR方法检测抗草甘膦转基因豆粕的灵敏度为0.1%。     

实时荧光定量PCR技术检测腐乳中大豆转基因成分

优化实时荧光定量PCR反应体系条件,运用此技术检测从腐乳中提取的DNA来判定腐乳样品是否含有大豆转基因成分。该检测方法特异性强、灵敏度高,方法检出限为0. 1%,而且操作简便,可以推广使用。     

豆腐中转基因大豆成分的检测

目的探索适合豆腐样品的DNA抽提方法并采用实时荧光聚合酶链反应(PCR)技术对豆腐试样中的转基因大豆成分进行检测。方法分别采用CTAB和SDS配制抽提缓冲液提取18个豆腐样品中的DNA,针对转基因大豆都含有大豆内源基因lectin及共同元件CaMV35S启动子、nos终止子及epsps基因进行实时荧光PCR扩增。结果 SDS法比CTAB法提取的豆腐DNA质量更好;18个豆腐样品均检测到了lectin,其中有2个样品检测到了CaMV35S启动子的荧光信号,4个样品检测到了nos终止子的荧光信号,所有样品均未扩增出epsps基因。结论 SDS法比CTAB法更适合于抽提豆腐样品的DNA,提取到的DNA可用于实时荧光PCR法检测豆腐内源基因和外源基因。     

应用PCR-ELISA技术检测转基因产品的研究

建立并优化了转基因大豆与玉米的DNA提取,CaMV35S启动子和T－NOS终止子的序列特点设计特异性引物与探针，应用PCR－ELISA检测技术，建立了转基因大豆与玉米中常用外源基因的快速检测体系，并应用于进出境产品的转基因检测实际工作中。结果表明，建立的PCR－ELISA法具有操作简便，灵敏特异，结果准确的，可对转基因大豆，玉米及其它转基因产品进行定性和定量检测。     

转基因大豆MON89788实时荧光PCR检测方法的建立

为实现转基因大豆MON89788的标识管理,针对转基因大豆MON89788的品系特异性序列设计引物和TaqMan探针,建立转基因大豆MON89788实时荧光聚合酶链式反应（polymerase chain reaction,PCR）检测方法,并对该方法的特异性、灵敏度和重复性进行检测。结果显示：建立的转基因大豆MON89788实时荧光PCR检测方法能扩增出127 bp的产物,特异性强,灵敏度达到0.1%,约为40 个单倍体基因组拷贝,检测重复性好,可成功应用于实际样品检测。因此,建立的转基因大豆MON89788实时荧光PCR检测方法可以应用于转基因大豆MON89788大豆及其制品的检测。     

大豆加工食品中转基因成分多重PCR检测体系的建立

以大豆内源基因 (Lectin)、筛选基因 3 5S启动子 (Cauliflowermosaicvirus 3 5S ,CaMV3 5S)、Nos终止子 (Nopalinesynthase,Nos)和外源基因 (5 enolpyruvylshikimate 3 phosphatesynthase ,Ep sps)为检测对象 ,通过对PCR扩增体系中各引物终浓度及PCR扩增过程中退火温度的探讨 ,研究了不同引物终浓度配比及退火温度对转基因大豆多重PCR检测的影响 ,建立了大豆加工食品中转基因成分多重PCR检测体系。结果表明 ,当各组引物的终浓度分别为 1 0、2 0、2 0、3 0 μmol/L即引物终浓度配比为 1∶2∶2∶3 ,退火温度为 5 5 4℃时 ,所建立的多重PCR检测方法能够有效地检测出大豆中的转基因成分 ,具有特异性好 ,简便 ,快速 ,准确等优点。     

Establishment of a quadruplex real-time PCR for screening of genetically modified tomatoes

With the increase in number of the genetically modified (GM) crops authorized worldwide and specific labeling legislation established by many countries, a reliable and efficient method for routine screening of raw material or processed food products needs to be developed. In this paper, a quadruplex quantitative real-time PCR (qPCR) system is described which allows simultaneous detection of one tomato endogenous gene and three most frequently used transgenic elements in GM products: cauliflower mosaic virus 35S promoter, Agrobacterium tumefaciens nopaline synthase terminator, and neomycin phosphotransferase II gene. The specificities of the assays are optimized and validated. In the quadruplex qPCR system, the detection ranges for all of the four genes were determined to be 8–80,000 copies per reaction. Finally, the established detection system was applied in amplification of exogenous and endogenous genes from 33 raw materials and 35 processed products samples. The results indicate that quadruplex qPCR method is feasible for screening of GM tomato products, even for some processed food. As this detection system could be easily applied to the detection of transgenic elements in other plant species, we expect it will meet the challenges of routine GM crop detection resulting from a rapid increase in the number of GM crops in the future.     

多重PCR 检测转基因水稻的转基因成分

以水稻内源基因SPS、外源抗虫基因Cry1Ab、外源抗虫基因Cry1Ab/Ac、外源抗虫基因Btc、报告基因GUS、NOS终止子和CaMV35S启动子为检测对象,设计7对引物,通过优化PCR扩增体系中不同引物浓度的配比及退火温度,建立水稻转基因成分的七重PCR检测体系。结果表明：建立的七重PCR体系能有效检测出水稻及其他作物(大豆、玉米、棉花籽、菜籽粕)中的转基因成分,检测过程简便、特异性好。     

Detection of genetically modified organisms in processed meat products on the Serbian food market

The addition of soybean proteins to processed meat products has significantly increased in recent years due to the interesting functional and nutritional properties of these vegetable proteins. Since the Roundup Ready (RR) soybean is the only transgenic soybean line approved for market in EU this work was aimed at monitoring its presence in meat products on the Serbian food market. The extracted DNA was analyzed using duplex polymerase chain reaction (PCR) with primer pairs aimed at the lectin gene and 35S promoter. Samples positive for the presence of GM soybean were subjected to a real-time quantification of the percentage of RR soya. The results indicated that out of fifty processed meat products examined, twelve gave positive results with 35S promoter and all contained RR soya below 0.1%.     

Event-Specific Qualitative and Quantitative Detection in Transgenic Soybean OsDREB3 Based on the 5′ Flanking Sequence

With the development of genetically modified organisms, labeling regulations have been introduced that require appropriate detection methods. Event-specific qualitative and quantitative polymerase chain reaction (PCR) detection methods have become the internationally agreed state-of-the art. Using adaptor PCR, we analyzed the flanking sequences of exogenous integrant in transgenic soybean OsDREB3, which has resistance genes. In this study 5′ region flanking sequences of exogenous gene were identified in the soybean OsDREB3 genome, which was integrated in chromosome 1 with an additional 394 bp insertion between soybean genomic DNA and exogenous gene. Based on these inserts and flanking sequences, the event-specific qualitative and quantitative PCR system was established for this line. In the conventional qualitative PCR assay, the event-specific primers designed were confirmed to be specific and the limit of detection (LOD) was 0.1%. In the quantitative real-time PCR assay, the LOD and the limit of quantity were 10 and 100 haploid genome copies, respectively. The goodness of the linearity and high efficiency of the PCR reaction indicated the utility of the established PCR system. This study provides two reliable methods and information for detection, identification, and quantification of the presence of non-authorized transgenic soybean OsDREB3.     

Detection of cauliflower mosaic virus by the polymerase chain reaction: testing of food components for false-positive 35S-promoter screening results

 Today DNA-based techniques are very common for the detection of genetically modified organisms (GMOs) in food products. For fast and easy detection of GMOs, polymerase chain reaction (PCR) screening methods, which amplify common transgenic elements, are applied in routine analysis. These techniques do not allow differentiation between GMOs and the natural occurrence of transgenic elements, such as the 35S-promoter of cauliflower mosaic virus (CaMV) or the NOS-terminator of Agrobacterium tumefaciens, and thus may result in false-positive detection of GMOs. In this study we evaluated three different existing 35S screening systems and report the development of two new CaMV-specific PCR systems. These PCR systems based on CaMV-specific genes allow the identification of positively screened 35S food samples as naturally virus-infected products or plants. Seven food samples tested positive in routine 35S screening analysis and negative in GMO specific systems were investigated using the new virus-specific PCR systems. In all seven samples CaMV was detected. Received: 26 April 1999 / Revised version: 28 June 1999     

Detection of Residues of Genetically Modified Soybeans in Breaded Fried Turkey Cutlets

The presence of genetically modified organisms (GMOs) in food products is usually ascertained by the polymerase chain reaction (PCR) or nested PCR if sensitivity has to be increased. Since most, if not all, GMO products are of plant origin, the target sequences are the 35S promoter or NOS terminator. The extreme sensitivity of nested PCR can be misleading if the results are not interpreted correctly, since contamination of non-GMO products with residual amounts of GMO may be positive. We report that breaded turkey breast cutlets labeled as containing GMO soybean products were actually prepared from wheat flour that had been contaminated with transgenic soybean.     

可视化膜芯片检测转基因大豆的研究

目的研究可视化膜芯片技术对转基因大豆及其制品的检测能力,验证该技术的灵敏度及可行性。方法利用可视化膜芯片对转基因大豆及其制品进行检测,并采用行业标准要求的实时荧光PCR方法进行对比验证。结果该技术具备典型外源基因片段的判定能力,能够用于大豆及其制品中转基因成分的检测,方法检出限为0.1%,比对验证实际样品的检测结果与行业标准荧光PCR法一致。结论该技术便捷、直观、准确,可用于大豆及其制品的转基因成分快速初筛与鉴定。     

转基因大豆Roundup Ready调控元件在食品加工过程中降解变化的研究

35S启动子可能会通过基因的水平转移插入到某一致癌基因上游，活化并导致癌症的发生。为了解转基因植物中调控元件的安全性问题，以转基因大豆Roundup Ready为实验材料，针对Roundup reaqdy转基因大豆中CaMV35S启动子及NOS终止子的序列，设计了不同长度片段的引物，通过对CaMV35S启动子和NOS终止子的PCR扩增，研究了豆腐、豆奶、豆粉3种大豆加工食品中磨浆、煮浆、调配、均质、杀菌、喷雾干燥等关键工艺对Roundup Reaqly大豆中调控元件的影响。结果表明调控原件在食品加工过程中的降解变化与其所处位置有较大关系。扩增长度相近的2个片段，包含大豆基因组。DNA序列的片段受加工过程的影响较小，在3种豆制品的所有加工过程中均能检测到。而只包含CaMV35S启动子序列的片段仅能在原料中检测到，原料经过磨浆后。片段大小降至200bp以下。NOS终止子受食品加工工艺的破坏和影响较小，在被检测食品的每一个加工过程中都能够检测到NOS终止子片段。