Development and Preliminary Application of SYBR Green I Real-Time Fluorescence Quantitative PCR Method for Detecting Porcine Parvovirus Virus

According to VP2 gene sequence of the porcine parvovirus virus strain NADL-2 （NC001718） available in GenBank （NC_001718）, a pair of specific primer was designed, and the target fragment of 431 bp was obtained by PCR amplification. The products were ligated with pMD18- T vector and then transformed into bacteria DH5α for recombinant plasmid extraction. After PCR identification and sequencing, recombinant plasmid was used as a standard template to establish the standard curve of SYBR Green I fluorescence quantitative PCR. Sensitivity test, specificity test and repeatability test were also determined. The results indicated that there was a good linear relationship between threshold cycle of the standard curve and template concentration, R2 =0.997 6. Tm ranged from 82.3 to 82.9 ℃, while the sensitivity was 72.1 copies/μl with good specificity and repeatability. The developed SYBR Green I real-time quantitative PCR method to detect PPV VP2 gene laid the basis for further studies on patho- oenesis, early clinical diaonosis of this virus and quantitative analysis of PPV infection.

Detection of Ratoon Stunting Disease in Virus-free Seedcane via Real-time Fluorescence Quantitative PCR

This study was to develop the real-time fluorescence quantitative PCR technique for detecting the ratoon stunting disease （RSD） in virus-free seedcane seedlings. Healthy tissue culture seedlings were obtained from six plants of sugarcane ROC22, which had been confirmed RSD-positive by detecting the sugarcane juice, by employing the sugarcane seedlings production protocol. Real-time fluorescence quantitative PCR was used to detect RSD pathogens in tissue culture sam- pies. The results showed that target fragment of RSD pathogens was not found in all 10 samples in real-time fluorescence quantitative PCR, with the Ct values of 37 - 39. The healthy tissue culture sugarcane seedlings do not carry RSD pathogens, indicating that adopting healthy seedcane seedlings production technique could thoroughly get rid of RSD pathogens.

Real-time fluorescent quantitative PCR非特异性扩增的研究进展

Real-time fluorescent quantitative PCR(RT-qPCR)因其高效快速、操作简便、高度敏感等优点获得广泛应用,但因其强大的放大功能而容易出现非特异性扩增的问题,尤其是荧光染料法中更加明显。文章对RT-qPCR的原理、非特异性扩增的发生因素、解决方案及该技术的应用前景进行了综述。

Application of Real-time Fluorescent Quantitative PCR in Plant

Real-time fluorescent quantitative PCR （RQ-PCR） is a detection method by adding fluorescent dye or fluorescent probe into the PCR reaction system, using fluorescent signal accumulation to monitor amplification reactions of PCR reaction process, and finally the unknown template can be quantitatively analyzed through the standard curve. So the detection level of PCR has improved from the qualitative to the quantitative. In order to provide a theoretical reference for further application, the principle, classification, advantages and disadvantages of RQ-PCR were intro- duced, and its application and progress in plants in recent years were reviewed.

Evaluation of Clinical Application of Chemiluminescence and Real-time,Fluorescence-based Quantitative PCR in Diagnosis of Epstein-Barr Virus lnfection

Objective:To compare the effects of clinical application of chemiluminescence and real-time,fluorescence-based quantitative PCR in the detection Epstein-Barr virus(EBV).Methods:The data of chemiluminescence and real-time fluorescent quantitative PCR.fromipaEsfwo were suspected of being infectea w1tn rito1 roro January 2016 to January 2019 in our hospital were analyzed.The specific stage of EBV infection was analyzed,and the differences in results of the two detection methods were compared.Results:Chemiluminescence method was used to detect EBV infection during the active phase.The sensitivity of the chemiluminescence method was 76.7%(56/73)and the real-time quantitative PCRmethod was 90.4%(66/73).There was a statistical difference between the two detection methods(P<0.05).Conclusion:There was no statistical difference in positive predictive values between the chemiluminescence method and the real-time,fluorescence-based quantitative PCR method in the detection of EBV infection,but the sensitivity of chemiluminescence method is slightly lower than the real-time quantitative PCRmethod.It is noteworthy that chemiluminescence method is convenient and fast while the real-time,fluorescence-based quantitative PCR method is more accurate,which can provide a more accurate reference for clinical treatment.

Detection of Lactobacillus acidophilus in Fermented Material by Real-time Fluorescent Quantitative PCR

The species distinctive PCR primer of Lactobacillus acidophilus （ L. acidophilus） was designed according to 16S rRNA gene sequences of conunon Lac- tobacillus species in fermented material. Bacterial genome DNA of separated L. acidophilus in fermented sample was taken as template, and L. acidophilus in fer- mented material was conducted the quantitative determination by real-time quantitative PCR （RT-PCR）. Analysis on RT-PCR results shown that contents of L. aci- dophilus in the test sample reached 1.5 billion CFU / g. Test results shown that contents of L. acidophilus in fermented material could be detected accurately by the established RT-PCR method in the test. indicating that the established RT-PCR method could be aookued to the detection of L. acidophilus in fermented material.

Application of Real-time Fluorescent Quantitative PCR in Studies on Plants

Real-Lime fluorescent quantitative PCR is a method for quantitative analysis of gene expression developed in recent years, which has been widely used in various fields such as basic scientific research, clinical diagnosis, disease study, drug research and development since its appearance. It starts relatively late in study on plants, but has already been used for analysis of gene expression in plants and gene identification of exogenous genes. The principles or advantages and dis- advantages of real-time fluorescent quantitative PCR, or its potential problems and condition optimizations in tests were introduced in this study, and then the appli- cation and prospect of real-time fluorescent quantitative PCR in study on plants were also been discussed.

Establishment of a Real-time Fluorescent Quantitative PCR Assay for Detection of Genetically Modified Maize Line MON88017

In order to improve the standardized technical systems of quantitative analyses for genetically modified organisms （GMOs） and products, ensure bio-safety and reduce ecological risk in China, a real-time fluorescent quantitative PCR assay was established for detection of genetically modified maize line MON88017. The established method was evaluated based on the specificity, sensitivity, accuracy and measurement uncertainty. The results showed that the established method had strong specificity in detection of genetically modified maize line MON88017. 1.50% MON88017 sample was detected with 29 replica- tions. The average measured value （ 1. 541% ） was close to the actual value （ 1.50% ） and the relative deviation was 2.70%. The variation coefficient of the measured value was 0.110 g ; the recovery was 100.00% and the measurement uncertainty was 0. 096. The limit of detection for genetically modified maize line MON88017 with the established method was 5 copies at the 97.5% confidence level. Thus, the real-time fluorescent quantitative PCR assay established in this study exhibited high specificity, accuracy and sensitivity, which could provide technical support for the safety supervision of genetically modified organ- isms and products in China.

Development of real-time PCR method for rapid detection and quantification of Heterosigma akashiwo

To rapidly detect the harmful algae H.akashiwo qualitatively and quantitatively, sequences of the 18S rDNA deduced from H.akashiwo were used for designing species-specific primers, and a RFQ-PCR (Real-time Fluorescent Quantitative Polymerase Chain Reaction) method was developed for quantitative detection of H.akashiwo. Primer H.akashiwo and TaqMan probe were designed, and the specificity of primer was checked with PCR. A calibration curve was constructed with cycle threshold value against visual counted cell number. And the value of the curve was tested with other H.akashiwo samples, which were assayed with both the RFQ-PCR method and visual count under microscope.

Primary application of a real-time quantitative polymerase chain reaction for the detection of human breast cancer related novel gene-Metadherin expression

Objective:The aim of this study was to detect the expression level of Metadherin (MTDH) in peripheral blood of the breast cancer patients by real-time fluorescence quantitative polymerase chain reaction (PCR),and to explore the relationship between expression of Metadherin gene in the patients peripheral blood and the clinic-pathological features in breast cancer. Methods:Real-time fluorescence quantitative polymerase chain reaction was employed to determine the expression level of Metadherin gene in 80 peripheral blood samples of breast cancer patients and healthy donors. Results:The expression of Metadherin gene in breast cancer patients peripheral blood were positive,in which 34 breast cancer patients were highly expressed,accounting for 55.7%,while the expression of Metadherin gene in normal females peripheral blood were negative,there was statistical significance (Ratio = 2.02±0.81,P < 0.05); Ratio of the Metadherin expression in breast cancer patients peripheral blood and the glyceraldehyde-3-phosphate dehydrogenase expression was 1.15 ± 0.36. REST software analysis showed that the expression of Metadherin gene was significantly up-regulated in breast cancer. Conclusion:The SYBR Green I quantitative real-time polymerase chain reaction method can successfully detect the expression level of Metadherin gene. Expression level of Metadherin gene in breast cancer patients peripheral blood is closely related to survival,and it maybe involved in the development of breast cancer and used as an indicator of prognosis.

牛冠状病毒TaqMan荧光定量PCR检测方法的建立及应用

为建立牛冠状病毒TaqMan荧光定量PCR检测方法,根据GenBank收录的牛冠状病毒AKS-01株N基因序列(KU886219)保守区设计特异性引物和探针,构建重组质粒并进行反应条件优化、特异性试验、重复性试验以及敏感性试验,建立一种检测BCoV的TaqMan荧光定量PCR方法。结果显示,建立的牛冠状病毒TaqMan荧光定量PCR检测方法特异性、敏感性和重复性均良好。该方法BCoV重组质粒标准品在5.75×10^(7)~5.75×10^(3)copies/μL时与Ct值呈现良好线性关系,该方法对牛轮状病毒、牛传染性鼻气管炎病毒、牛病毒性腹泻病毒、牛副流感病毒3型均无交叉反应,特异性良好;该方法对BCoV重组质粒标准品最低检测限为5.75×10^(1)copies/μL;批内和批间重复性试验结果稳定,变异系数均小于2%。利用所建立的TaqMan荧光定量PCR方法对收集的132份样品进行检测,与常规PCR相比,两者符合率为96.21%,可为BCoV的临床检测和流行病学调查提供技术支持。

水禽细小病毒SYBR Green Ⅰ荧光定量PCR检测方法的建立与应用

为了建立水禽细小病毒(WPV)快速检测方法,根据序列比对结果在水禽细小病毒NS基因SF3保守区域内设计特异性引物,建立SYBR Green Ⅰ荧光定量PCR通用检测方法。该方法的扩增效率(E)为90.0%,相关系数(R~2)=0.99,标准曲线方程为y=-3.607x+38.77;除WPV出现S形扩增曲线外,新城疫病毒(NDV)、H9亚型禽流感病毒(H9 AIV)、鸭坦布苏病毒(DTMUV)、鸭肝炎病毒(DHAV)、鸭肠炎病毒(DEV)、鸭呼肠孤病毒(DRV)样品均未出现S形阳性扩增曲线;批内变异系数(CV)为0.15%~0.23%,批间变异系数为0.09%~0.28%。结果表明,SYBR Green Ⅰ荧光定量PCR检测方法重复性好、灵敏度高和特异性强。临床样品检测结果表明,SYBR Green Ⅰ荧光定量PCR与普通PCR的符合率达98.4%,灵敏度是普通PCR的1 000倍。SYBR Green Ⅰ荧光定量PCR检测方法不仅能定性检测WPV,还可以进行定量检测,可用于种鸭场、种鹅场的WPV净化检测,也可用于WPV临床大量样品的快速检测。

美洲鳗鲡腺瘤病毒(AEAdoV)普通PCR和SYBR Green I实时荧光定量PCR检测方法的建立及应用

为建立美洲鳗鲡腺瘤病毒(AEAdoV)的检测方法,根据AEAdoV福建株(AEAdoVFJ)的superfamily 3 helicases(S3H)序列,设计引物,建立了AEAdoV的普通PCR和qPCR检测方法;进一步评价检测方法的灵敏性、特异性及重复性,利用2种方法对美洲鳗鲡“出血性烂鳃”病料进行了检测,并对美洲鳗鲡体内不同组织的病毒含量进行分析。结果显示,普通PCR扩增的目的片段长度约300 bp,利用其构建的qPCR质粒标准品,其拷贝数与qPCR阈值循环数(C_(t))线性关系良好,线性范围广,标准曲线相关系数(R2)达到0.999,扩增效率为105.067%。建立的普通PCR法和qPCR的最低检测AEAdoV拷贝数分别为100个和10个。2种方法均可特异性检测AEAdoV,而对蛙虹彩病毒(RGV)、鳗鲡疱疹病毒(AngHV)、鲤疱疹病毒(KHV)、对虾白斑综合征病毒(WSSV)、日本鳗鲡内皮细胞坏死病毒(JEAdoV)和花鳗鲡腺瘤病毒(MEAdoV)均无扩增反应。qPCR法的组内和组间变异系数均小于2%,表明其重复性良好。临床应用结果显示,35份美洲鳗鲡“出血性烂鳃”病料,采用普通PCR法的AEAdoV检出率为82.8%,而qPCR法的AEAdoV检出率为97%。对美洲鳗鲡不同组织的病毒含量分析结果显示,心脏、肝脏、鳃、鳍的AEAdoV相对含量较高,而黏液、皮肤和脾脏的病毒含量相对较低。研究表明,建立的AEAdoV的灵敏度高、特异性强的普通PCR和qPCR检测方法,证实AEAdoV与美洲鳗鲡“出血性烂鳃”病密切相关,且在感染鳗鲡主要组织中都存在。实验结果对于研究AEAdoV的致病性,开展其流行情况和病原学情况分析具有重要意义。

三疣梭子蟹十足目虹彩病毒1 SYBR Green I荧光定量PCR检测方法的建立及初步应用

为建立十足目虹彩病毒1(decapod iridescent virus 1,DIV1)的SYBR GreenⅠ荧光定量PCR检测方法,根据DIV1的MCP和ATPase基因序列,设计并筛选出引物,以制备的DIV1阳性质粒标准品为模板构建标准曲线,建立DIV1的SYBR Green I qPCR方法,并对该方法进行临床初步应用。结果显示,建立的qPCR方法阈值循环数(cycle threshold value,Ct)与标准品拷贝数的对数线性关系良好,标准曲线相关系数(R^(2))为0.999;对DIV1阳性的虾蟹核酸样本能够进行特异性扩增,但对传染性脾肾坏死病毒(infectious spleen and kidney necrosis virus,ISKNV)和白斑综合征病毒(white spot syndrome virus,WSSV)阳性核酸样本均无扩增;最低检测限为9.77 copies/μL;Ct值的组内和组间变异系数均小于1%。运用该方法对70份疑似感染DIV1的虾蟹类样本进行DIV1检测,该方法阳性率为48.57%,与套式PCR检测方法的阳性率一致;利用建立的方法对DIV1阳性三疣梭子蟹的血淋巴、肝胰腺及心脏等组织进行定量检测分析,结果显示各组织中均存在DIV1,其中血淋巴中DIV1平均拷贝数最高。研究表明,建立的SYBR GreenⅠ荧光定量PCR方法特异性强、灵敏度高、重复性好,可用于对DIV1的快速、定量检测,对十足目虹彩病毒病的诊断和防控具有重要意义。

O型口蹄疫病毒和塞内卡病毒双重荧光定量RT-PCR检测方法的建立

为建立O型口蹄疫病毒(FMDV-O)和塞内卡病毒(SVV)快速鉴别检测方法,本实验根据FMDV-O VP2基因序列和SVV P3基因序列,采用Primer Express3.0软件分别设计引物与探针,并经各反应条件的优化初步建立了可同时鉴别检测FMDV-O和SVV的双重荧光定量RT-PCR方法。利用该方法检测临床常见猪病毒,结果显示可同时检测出FMDV-O和SVV核酸,且与猪水泡性口炎病毒(VSV)、猪水疱病毒(SVDV)、猪瘟病毒(CSFV)、猪繁殖与呼吸综合征病毒(PRRSV)、猪细小病毒(PPV)、A型口蹄疫病毒(FMDV-A)、A-1型口蹄疫病毒(FMDVA-1)核酸均无交叉反应,并可检测到FMDV-O PanAsia株、cathay株、Ind-2001株和Mya-98株等主要流行株,特异性强;该方法对含FMDV-O和SVV拼接质粒标准品的最低检测限为7.17×10^(2)拷贝/μL,敏感性高;利用该方法检测了同一时间和不同时间提取的3种不同浓度的质粒标准品,结果显示批内和批间重复性试验Ct值的变异系数均小于3%,重复性好。利用本实验所建立的方法对30份临床样品进行检测,结果与各病毒单一荧光定量RT-PCR检测结果一致。本研究建立的FMDV-O和SVV双重荧光定量RT-PCR方法能够快速准确的鉴别检测FMDV-O和SVV,为口岸检疫的快速通关提供了技术手段。

鸡圆环病毒SYBR GreenⅠ实时荧光定量PCR检测方法的建立

为快速准确检测鸡圆环病毒(CCV),试验根据CCV Rep基因设计特异性引物,以CCV阳性病料提取的DNA为模板进行PCR扩增,构建CCV重组质粒,建立检测CCV的SYBR GreenⅠ实时荧光定量PCR方法。结果显示:试验建立的方法对2.87×10^(8)~2.87×10^(1)copies/μL浓度范围的CCV重组质粒标准品呈现良好的线性关系,相关系数(R^(2))为0.9936,灵敏度比常规PCR高100倍;该方法对鸡传染性贫血病毒、新城疫病毒、传染性支气管炎病毒等常见鸡病毒性病原以及多杀性巴氏杆菌、禽致病性大肠杆菌、鸡白痢沙门氏菌无特异性扩增,批内和批间变异系数均不超过1%;该方法对60份疑似CCV感染临床样品检测结果显示,CCV阳性检出率(16.67%)高于常规PCR。上述结果表明,研究建立的CCV SYBR GreenⅠ实时荧光定量PCR方法具有良好的敏感性、特异性和重复性,检出限为2.87×10^(1)copies/μL,可以用于CCV的快速定量检测。

实时荧光定量PCR检测猴痘病毒的方法研究

目的建立猴痘病毒(mpox virus)的实时荧光定量PCR(RT-PCR)检测方法。方法以猴痘病毒F3L基因为靶序列,设计特异性引物和探针,建立猴痘病毒RT-PCR检测方法,并对方法的灵敏度、特异性和重复性进行检测;对疑似猴痘阳性的人脓拭子临床样本核酸进行检测,对RT-PCR方法检测临床样本能力进行评价。结果本研究建立的RT-PCR检测方法可实现猴痘病毒的特异性检测,与天花、痘苗、牛痘等其他正痘病毒无交叉反应,检测重复性好,最低检测限为103copies/μL。可以对人皮肤拭子样本中的猴痘病毒进行准确检测。结论本研究建立了猴痘病毒的RT-PCR检测方法,可在临床样本中快速、特异、灵敏的检测猴痘病毒。

副结核分支杆菌实时荧光定量PCR检测方法的建立及应用

为加强副结核分支杆菌(MAP)的检测、监测与防控,建立MAP荧光定量PCR(qPCR)检测方法,根据国内MAP流行菌株特异性插入序列IS900设计1对特异性引物和探针,构建重组阳性质粒用作建立qPCR的模板,优化反应体系和条件,验证该方法的特异性、敏感性和重复性。结果显示,该方法最低检测限为5拷贝/μL;重复试验中批内和批间变异系数均小于4%;与牛传染性鼻气管炎病毒、牛副流感病毒3型、牛轮状病毒、牛病毒性腹泻病毒、牛支原体、肺炎克雷伯菌和曼氏杆菌等病原检测无交叉反应,能特异性检出MAP。应用建立的qPCR开展了内蒙古自治区6个市的MAP临床样品检测和流行情况分析,结果显示MAP平均阳性率为0.85%(6/704)。结果表明,成功建立了MAP的实时荧光定量PCR检测方法,可用于临床中MAP的监测和调查,为MAP疾病诊断与监控提供了快捷的方法。

高危型HPV感染临床检验中实时荧光定量PCR检测法的作用

目的分析高危型人乳头瘤病毒(HPV)感染临床检验中实时荧光定量聚合酶链式反应(PCR)检测法的作用。方法选取80例疑似高危型HPV感染患者,均接受第二代杂交式捕获法(HCⅡ)、实时荧光定量PCR检测,以病理检查结果为金标准,分析实时荧光定量PCR检测价值。结果实时荧光定量PCR检验准确率97.50%、敏感度98.51%、特异度92.31%,均显著高于HCⅡ的78.75%、88.06%、38.46%(P<0.05);实时荧光定量PCR诊断检出率CINⅠ100%、慢性宫颈炎92.31%,均显著高于HCⅡ的88.10%、46.15%(P<0.05)。结论应用实时荧光定量PCR检测法可明显提高高危型HPV感染患者的临床检验准确性,提高治疗方法的针对性。

实时荧光定量PCR定量方法研究进展

实时荧光定量PCR以其特异性强、灵敏度高、重复性好、定量准确、速度快、全封闭反应等优点而成为了分子生物学研究中的重要工具,综述了实时荧光定量PCR技术及其定量方法的研究进展,并展望了其应用前景。