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。     

应用单管半巢式PCR技术筛查转基因食品

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）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CaMV35S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CaMV35S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。     

聚丙烯酰胺凝胶电泳在转基因大豆检测中的应用

利用PCR技术，对转基因大豆中CaMV35S启动子、NOS终止子、CP4-EPSPS和大豆凝集素基因进行了定性检测，并且以大豆凝集素基因为内置标准检测了CaMV35S启动子。采用非变性聚丙烯酰胺凝胶电泳和琼脂糖凝胶电泳对PCR扩增产物进行分析，并对两种电泳进行了比较。聚丙烯酰胺凝胶电泳有利于提高定性PCR筛选方法的准确性。     

PCR法定性检测大豆食用油中转基因成分

针对大豆食用油中核酸含量低且被严重破坏、DNA难以提取的问题,对CTAB法进行优化,有效从食用油中提取到可用于PCR扩增反应的DNA模板。同时定性检测出大豆内源基因lectin,外源调控序列启动子CaMV35S、终止子Nos及目的基因CP4-EPSPS序列,成功建立了基于PCR技术在大豆食用油中快速检测转基因成分的方法。     

植物油DNA的高效提取方法研究

针对植物油中DNA含量极低、DNA序列片段短、破坏严重的特点,以食用植物油为原料,旨在建立一种从植物油中稳定、高效提取DNA的方法。实验采用硅膜吸附柱法提取植物油基因组DNA,PCR扩增其相应内源基因进行质量鉴定,再针对通用的外源基因CaMV35S启动子进行PCR、LAMP和实时荧光PCR检测对该方法进行评价。结果表明:该方法提取的DNA质量可靠,采用PCR、LAMP和实时荧光PCR技术成功地检测出了植物油中的CaMV35S启动子。因此,硅膜吸附柱法提取的植物油DNA可以作为PCR、LAMP、实时荧光PCR扩增模板用于转基因成分的检测,该方法经济、稳定、安全,为植物油的基因检测奠定了基础。     

豆粕中转基因成分检测技术研究

针对豆粕中核酸含量低且被严重破坏,DNA难以提出的问题对CTAB法进行优化,有效地从豆粕中提取到可以用于扩增反应的DNA。同时定性检测出外源调控序列CaMV35S启动子和NOS终止子及目的基因Cp4-EPSPS序列,成功建立了豆粕中转基因成分的检测方法。     

转基因玉米DNA检测芯片的研究

根据转基因玉米中所转入的外源基因,选择CaMV35S启动子、NOS终止子、PAT基因和目的基因IVS2/PAT、CDPK/CryIA(b)、Maize genome/CaMV35S、PAT/CaMV35S1、Cry9C/CaMV35S!以及内源IVR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DIG-dUTP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0.1%.     

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。     

花椰菜花叶病毒CaMV 35S启动子LAMP检测方法的建立

针对花椰菜花叶病毒(CaMV)35S启动子的保守序列设计特异性引物,并进行条件优化,建立CaMV35S启动子的LAMP检测方法。该方法具有良好的特异性,检测灵敏度可达0.002%。对80份各类植物及其加工品进行检测,检测结果与实时荧光PCR法完全相符。CaMV35S启动子的LAMP检测方法,在检验检疫行业和食品加工业具有广阔的应用前景,对于加强转基因产品检测监管,促进进出口贸易具有重要意义。     

转基因"华番一号"番茄的筛选和特异性的定性、定量PCR检测方法

为给转基因植物监测提供技术支持，建立了转基因“华番一号”番茄筛选和特异性的定性、定量PCR检测方法。转基因“华番一号”的筛选PCR检测主要以转基因通用元件CaMV35S启动子和NOS终止子为目的基因片段，特异性PCR检测以转基因外源重组子的CaMV35S启动子和反义EFE基因的相邻序列为目的片段；实验同时设立番茄的LAT52基因为转基因番茄定性、定量PCR检测的内对照基因。在所建立的PCR检测体系中，定性PCR筛选和特异性检测的检测极限为68个拷贝，实时定量PCR方法的检测极限为3个拷贝；筛选定量．PCR检测的定量极限为3个拷贝，特异性定量PCR检测的定量极限为25个拷贝。最后通过对2个已知含量的转基因番茄“华番一号”混合试样的检测，证明了该体系可以有效地用于转基因番茄“华番一号”的筛选和特异性的定性、定量PCR检测。     

Optimization of the PCR for detection of Staphylococcus aureus nuc gene in bovine milk

Staphylococcus aureus is an economically important and a major mastitis-causing pathogen that also poses food safety and antimicrobial resistance threats. Substances in mastitic milk inhibit the Taq DNA polymerase reaction (Taq PCR) making it of limited use for detecting S. aureus mastitis. In the study reported here, a set of oligonucleotide primers of 21 and 24 bases was used in Taq-PCR to amplify DNA from S. aureus (isolates from bovine mastitis). A specific amplicon of 270 bp was generated as predicted. Replacing Taq DNA polymerase with Thermus thermophilus (Tth) DNA polymerase alone (Tth-PCR) raised the sensitivity of S. aureus detection in milk from experimentally infected cows from 65 to 80%. Combining the use of Tth DNA polymerase and the purification of crude DNA extract using Chelex-100 before PCR raised the sensitivity to 100%. In a random survey involving 100 milk samples from cattle not infected with S. aureus, the test was 100% specific. With milk samples from clinical cases of bovine mastitis, 100% sensitivity and specificity were also observed. It is concluded that Tth-PCR on milk samples with the purification of crude DNA extracts using Chelex-100 is as sensitive as but faster than conventional milk bacteriological culture techniques and is highly specific. The modified PCR correlates with elevated somatic cell counts, detects evidence of chronic and resolving infection based on S. aureus-specific DNA and circumvents the endogenous inhibitory effects of milk.     

大豆粉转基因成分能力验证样品的检测分析

目的 提高实验室对转基因大豆定性检测的准确性和检测人员专业技术水平, 增强实验室竞争力。方法 通过核酸蛋白仪器分析法和单重实时荧光PCR (simplex real-time fluorescence PCR)法对样品内源基因扩增的循环阈值的影响来比较2种方法, 分析2种DNA提取试剂盒的提取质量。对标准SN/T 1204-2016《植物及其加工产品中转基因成分实时荧光PCR定性检验方法》扩增反应体系中DNA模板量进行优化后, 对样品进行检测。再依据标准SN/T 1202-2010《食品中转基因植物成分定性PCR检测方法》的要求, 对样品进行检测。最后对2个标准的检测结果进行比对。结果 通过内源基因扩增循环阈值的数据确认, 更能准确反映试剂盒提取的DNA是否满足后续外源基因的分析检测要求。2种标准方法对19-N578和19-M913 2个待测样品的检测显示3种外源基因CaMV35S、NOS、CP4-EPSPS均为阴性, 19-N578和19-M913待测样品均为非转基因大豆。结论 本次能力验证获得满意评价。DNA提取质量的评估, 体系中DNA模板量的优化, 检测方法的选择和实验的质量控制都是影响能力验证结果的重要因素。     

大豆及其制品中转基因成分的二重PCR检测

为了建立能同时检测多种转基因成分的二重PCR检测方法,以转基因大豆(RoundupReady品种)为实验材料,优化了二重PCR的反应体系和反应条件,包括引物浓度、TaqDNA酶用量和退火温度等;比较了二重PCR和单一PCR的灵敏度和检测含量。结果表明:二重PCR的灵敏度和检测含量与单一PCR的相当;用建立的二重PCR方法从大豆、豆腐、豆粕和油炸豆腐中筛选出含转基因成分的阳性样品;二重PCR与单一PCR相比,具有节约试剂、省时等特点,在转基因产品检测上具有很好的推广价值。     

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。     

Comparison of TaqMan Salmonella amplification/detection kit with standard culture procedure for detection of Salmonella in meat samples

We evaluated the TaqMan PCR Salmonella amplification/detection kit (PE Applied Biosystems) for rapid detection of Salmonella from a variety of meat samples. This system uses the 5' nuclease activity of Taq DNA polymerase, which digests an internal fluorogenic probe to monitor the amplification of the target gene. The detection sensitivity of the kit, using 2 kinds of DNA extraction protocols, was compared with that obtained with 4 protocols of official culture methods. A total of 98 meat samples (16 raw beef, 31 pork and 51 chicken) were tested. The results of the TaqMan PCR method and the combined results of the 4 cultural protocols showed excellent agreement. However, no single culture protocol showed optimal recovery of Salmonella comparable to the PCR method. These results suggest that the TaqMan PCR method is a reliable and rapid method useful for detecting Salmonella in meat products.     

环介导等温扩增技术在食品安全检测领域的应用研究进展

环介导等温扩增技术(Loop-mediated isothermal amplification,LAMP)是近年发展起来的一种新型核酸检测技术。其采用特异识别靶序列上6个位点的4条引物和一种具有链置换活性的DNA聚合酶,在等温条件下进行核酸扩增,与传统核酸检测技术(PCR法、实时荧光定量PCR法)相比,具有操作简单、特异性强、灵敏度高、可肉眼判读结果等优点。核酸检测是食品安全检测技术的一个重要手段,本文综述了LAMP技术在食品微生物检测、转基因成分检测、过敏原成分检测和动物源性成分检测领域的应用研究进展,探讨了LAMP技术在食品检测领域的发展前景,以期为食品快速、高通量检测技术建立提供参考。     

双正交优化多重PCR检测食源性致病菌的研究

为了建立快速检测食源性致病菌的多重PCR检测方法,根据沙门氏菌fimY基因、单增李斯特氏菌hlyA基因和小肠结肠炎耶尔森氏菌ail基因设计3对特异性引物,利用双正交法分别对多重PCR反应体系中的3对引物比进行L9(33)正交优化和Taq酶、dNTPs、镁离子、混合引物的添加量进行L16(44)正交优化,并对Buffer的反应浓度进行优化。结果扩增出了3条特异性目的条带,建立的多重PCR方法具有很好的特异性。人工污染食品,9h富集培养增菌后的检出限可达100cfu/g。因此,该检测方法具有较强的实际应用价值,为检测多种食源性致病菌提供了有效的方法参考。     

Establishment and application of a polymerase chain reaction for the identification of beef

A polymerase chain reaction (PCR) based method for the identification of beef by amplification of bovine 1.709 satellite DNA was established. The method not only was able to amplify raw beef DNA, but also cooked or autoclaved meat DNA. The sequence selected for amplification consisted of a 218 bp DNA fragment lying in the 1.709 satellite DNA of bovine. A pair of synthetic oligonucleotides flanking this sequence were used as printers, and genomic DNA extracted from beef samples employed as templates. Each batch of reaction mix contained Taq DNA polymerase, a buffer component, deoxynucleotide triphosphates, genomic DNA template and a pair of bovine oligodeoxynucleotide primers in a final volume of 50 μl. The amplification of bovine DNA was performed by using 33 cycles of denaturation at 94°C (40 s), annealing at 53.5°C (50 s) and extension at 72°C (60 s), with a 7 min extension at 72°C in the last cycles. The amplified products were subjected to rapid electrophoresis in 3% agarose gel and visualized under ultraviolet illumination after ethidium bromide staining. A Hae Ш restriction endonuclease test was done to verify the specificity of the PCR amplification, and the expected DNA fragments were produced. The specificity test demonstrated that this method was positive for bovine, buffalo and yak meat DNA, but negative for equine, sheep, goat, camel, swine, deer and mouse meat DNA, etc. At least 33.6 fg of DNA from raw beef samples and 0.32 pg of DNA from cooked or autoclaved beef samples were detected, respectively, by PCR. We tested 103 beef samples by PCR and obtained 100% correct identification. The method needed only 6 h for detection of meat products of all kinds. The results showed that the PCR method was sensitive, specific, convenient and rapid, so it may be suitable for rapid identification of beef.     

转基因玉米的多重PCR－毛细管电泳紫外检测技术研究

建立了转基因玉米Ly038、Mon863和Mon810的品系特异性基因多重PCR产物的毛细管电泳-紫外检测方法。根据三种转基因玉米的基因序列设计多重PCR引物,优化PCR扩增体系和条件,以8.0g/L羟乙基纤维素为筛分介质,用毛细管电泳-紫外检测法同时检测出三种玉米的品系特异性基因,11.195min内即可完成检测。用Origin软件对电泳结果进行分析并得出不同范围的DNA曲线方程,样品出峰时间的相对误差在1.03%～5.02%之间。并对纯化前后的样品进行了毛细管电泳分离的对照,发现PCR产物纯化后更适于紫外检测的毛细管电泳。多重PCR具有节约模板、节省试剂和缩短检测时间的优点,毛细管相对于传统的琼脂糖凝胶电泳,具有高效、快速、灵敏且经济环保的优点,所以此方法可广泛地应用于食品安全检测和临床检验等领域中。     

A detection method for recombinant DNA from genetically modified maize CBH351

A method using polymerase chain reaction (PCR) was designed for the detection of genetically modified maize CBH351, which has not authorized as safe for use in foods and feeds in Japan yet. We analyzed a recombinant DNA (r-DNA) sequence introduced into CBH351 maize and designed specific primer pairs to amplify a segment including part of the r-DNA. The PCR products obtained by using the designed primer pairs are specific for CBH351 and should prevent false positive results caused by other maizes and other main cereal crops. The r-DNA introduced into CBH351 could be detected from maize samples containing 0.05-0.1% CBH351 maize. This sensitivity is theoretically equivalent to a level of several genome copies and so this technique is a very efficient means to detect CBH351 maize.