荧光分子信标探针检测双歧杆菌的研究

根据双歧杆菌高度保守的寡核苷酸序列,构建一枚荧光分子信标探针,并对探针的性能进行测定分析,利用实时PCR技术对双歧杆菌进行检测。研究结果表明,所构建的分子信标设计合理,合成正确,性能稳定,S/N>20,其发卡既可以闭合也可以打开,符合实时PCR过程对分子信标的要求;该信标探针对双歧杆菌具有很好的稳定性及特异性,通过实时PCR扩增能有效地将双歧杆菌和非双歧杆菌区别开。因此,荧光分子信标探针可用于对双歧杆菌的检测。     

Establishment of Digital RT-PCR Assay for Detection of Swine Influenza Virus H3N2 Subtype

A new assay for the detection of swine influenza virus (SIV) was developed with a novel nucleic acid probe——Molecular beacon in this study. The specific primers and molecular beacon probes were designed according to the conserved region of H3 and N2 genes of SIV H3N2 subtype. A digital RT-PCR assay was developed for detection of SIV H3N2 subtype. The results showed that SIV H3N2 subtype could be identified simultaneously on this microarry with high sensitivity and reproducibility,which could reach to 10⁶ dilute viruse. The conclusion was that the digital RT-PCR method could analyze quantitatively the RNA templates.On the identification of H3N2 SIV,the digital RT-PCR method was much more scientific than Real-time quantitative PCR method.     

Real-time NASBA for Detection of Strawberry Vein Banding Virus

An assay for the detection of Strawberry vein banding virus (SVBV) in Fragaria spp. based on nucleic acid sequence based amplification (NASBA) and real-time detection using molecular beacons (real-time NASBA) is described. This assay was compared both with biological indexing, the current method for certification of SVBV, and a newly optimised PCR-based detection method. Performance of the assay was tested on three SVBV isolates in Fragaria indicator plants and 317 field strawberries from five European countries. The assay was shown to be SVBV-specific, testing negative for other common aphid-borne strawberry viruses. The virus was detected in purified total RNA preparations diluted a millionfold, which is an amount equivalent to 1ng of fresh material. The real-time NASBA method developed here offers the potential of a fast, sensitive and reliable approach for the routine diagnosis of strawberry stock material.     

DGPS在精确农业应用中定位精度的实验研究

GPS是GIS的重要数据来源，其定位精度对实施精确农业有着至关重要的作用。为此介绍了差分GPS的构成与具体设置，并通过具体实验进行对比分析，说明了其定位精度及误差，为实践精确农业提供了精度与理论保障。     

Development and validation of a real‐time PCR assay for the detection of Aeromonas salmonicida

A real‐time PCR assay using a molecular beacon was developed and validated to detect the vapA (surface array protein) gene in the fish pathogen, Aeromonas salmonicida. The assay had 100% analytical specificity and analytical sensitivities of 5 ± 0 fg (DNA), 2.2 × 10⁴ ± 1 × 10⁴ CFU g^?1 (without enrichment) and 40 ± 10 CFU g^?1 (with enrichment) in kidney tissue. The assay was highly repeatable and proved to be robust following equivalency testing using a different real‐time PCR platform. Following analytical validation, diagnostic specificity was determined using New Zealand farmed Chinook salmon, Oncorhynchus tshawytscha (Walbaum), (n = 750) and pink shubunkin, Carassius auratus (L.) (n = 157). The real‐time PCR was run in parallel with culture and all fish tested were found to be negative by both methods for A. salmonicida, resulting in 100% diagnostic specificity (95% confidence interval). The molecular beacon real‐time PCR system is specific, sensitive and a reproducible method for the detection of A. salmonicida. It can be used for diagnostic testing, health certification and active surveillance programmes.     

实时荧光定量检测技术及应用

随着现代医学和分子生物学的飞速发展，近年来在病原体的鉴别诊断方面，不断研究和开发了一些先进的检验新技术，TaqMan荧光探针脱颖而出。这项新技术日臻成熟并开始大量应用于临床实践中。它实时、准确、定量和高度重现性的特点优于其它核酸扩增技术，在医学检验领域中颇受关注，在兽医诊断应用中也开始被采用。文章就这一新的检测技术的原理、特点、应用和研究进展进行综述并与常规PCR检测技术进行对比。     

分子信标荧光定量PCR检测H3N2亚型猪流感病毒方法的建立

利用新型荧光探针—分子信标,建立一种检测猪流感病毒的新方法。根据H3N2亚型猪流感病毒（SIV）的HA和NA基因的保守基因序列,分别设计并合成了特异性引物和分子信标探针,利用实时荧光定量PCR技术检测H3N2亚型SIV。构建重组质粒pSK-H3和pSK-N2并绘制标准曲线。结果显示,该检测方法的敏感性达到102拷贝/μL;与其它主要相关病毒均不发生交叉反应,批内和批间试验的重复性变异系数（CV）均小于3％,表明该方法灵敏度强、特异性好。此方法的建立将为流感病毒H3N2亚型定型检测提供一种快速有效的方法。     

数字RT-PCR技术检测H3N2亚型猪流感病毒方法的建立

试验旨在利用新型荧光探针--分子信标,建立一种检测猪流感病毒的新方法。根据H3N2亚型猪流感病毒（swine influenza virus,SIV）的H3和N2基因的保守基因序列,分别设计并合成了特异性引物和分子信标探针,利用数字RT-PCR技术检测H3N2亚型SIV。结果显示,该数字RT-PCR检测方法与其他主要相关病毒均不发生交叉反应,重复性良好;对猪H3N2流感病毒而言,最低可检测到10⁶倍稀释的病毒株。数字RT-PCR方法能够对RNA模板定量分析。在H3N2 SIV的鉴定上,数字RT-PCR方法较实时荧光定量PCR方法更灵敏、准确。