Study on PCR rapid molecular detection technique of Meloidogyne vitis

Meloidogyne vitis is a new root-knot nematode parasitic on grape root in Yunnan Province, China.  In order to establish a rapid, reliable and specific molecular detection method for M. vitis, the species-specific primers were designed with rDNA-ITS (ribosomal DNA internal transcribed spacer) gene fragment as the target.  The reaction system was optimized and the reliability, specificity and sensitivity of primer were testified, therefore, a rapid PCR detection method for M. vitis was established.  The result showed that the optimal annealing temperature of the primers was 53°C, which was suitable for the detection of different life stages of M. vitis.  Specificity test showed that the specific fragment size of 174 bp was obtained from M. vitis, but other five non-target nematodes did not have any amplification bands, thus effectively distinguish M. vitis and the other five species, and could specifically detect the M. vitis from mixed populations.  Sensitivity test showed that this PCR technique could detect the DNA of a single second-stage juvenile (J₂) and 10^–4 female.  Futhermore, this PCR technique could be used to detect directly M. vitis from soil samples.  The rapid, sensitive and specific PCR molecular detection technique could be used for the direct identification of a single J₂ of M. vitis and the detection of M. vitis in mixed nematode populations and the detection of two J₂s or one male in 0.5 g soil samples, which will provide technical support for the investigation of the occurrence and damage of M. vitis and the formulation of efficient green control strategies.     

Xeroderma pigmentosum: a rapid sensitive method for prenatal diagnosis

When normal human cells, capable of repairing ultraviolet-induced lesions in their DNA, are incubated in the thymidine analog 5-bromodeoxyuridine after ultraviolet irradiation, the analog is incorporated into the repaired regions. When such repaired cells are subsequently irradiated with 313-nanometer radiation and placed in alkali, breaks appear in the DNA at sites of incorporation of 5bromodeoxyuridine, inducing a dramatic downward shift in the sedimentation constant of the DNA. Cells from patients with the disease xeroderma pigmentosum, which causes sensitivity to ultraviolet, are incapable or only minimally capable of repair; such cells incorporate little 5-bromodeoxyuridine into their DNA under these conditions and, upon 313-nanometer irradiation and sedimentation in alkali, exhibit only minor shifts in DNA sedimentation constants. When fibroblasts developed from biopsies of normal skin and of skin from patients with xeroderma pigmentosum, as well as cells cultured from midtrimester amniotic fluid, were assayed in this fashion unequivocal differences between normal and xeroderma pigmentosum cells were shown. Xeroderma pigmentosum heterozygotes are clearly distinguishable from homozygous mutants, and results are available 12 hours after irradiation.     

光谱技术结合化学计量学分析方法快速检测阿维菌素的试验研究

生物农药阿维菌素是一种微溶于水的高毒杀虫剂,有广谱、高效等特点,在防治水稻螟虫,稻纵卷叶螟方面表现优异,但对水生生物高毒。为了探讨利用光谱技术现场快速检测水体中生物农药阿维菌素的可能性,测定了其在紫外/可见光波长范围内的不同浓度吸光度光谱数据,建立其快速有效的定量分析模型。使用不同光程比色皿采集一定浓度范围的阿维菌素农药样本光谱数据进行对比,得到最佳光谱数据用于后续定量处理分析。将波长范围为200～500 nm的光谱数据采用Savitzky-Golay卷积平滑法（S-G平滑法）进行数据预处理,将原始光谱数据和S-G平滑法预处理后的光谱数据校正集和预测集分别按不同比例采用Sample set partitioning based on joint x-y distance(SPXY)算法进行样本集划分,并分别建立PLS模型进行比较。再将划分样本集后优选出的光谱数据采用主成分分析（Principle component analysis,PCA）结合马氏距离阈值法（Mahalanobis Distance,MD）,即PCAMD算法剔除异常样本,再将剔除异常样本后的光谱数据采用竞争性自适应重...     

布鲁氏菌病病原快速检测方法的建立

根据编码牛种布鲁氏菌外膜蛋白（OMP-2）基因的核苷酸序列设计1对PCR引物,并对PCR扩增条件进行优化,建立了快速检测布鲁氏菌病病原的PCR方法。特异性检测表明,该引物对牛种、羊种、猪种布鲁氏菌制备的模板DNA均能扩增出193bp目的基因片段,但不能扩增大肠杆菌、金黄色葡萄球菌、大肠结肠炎耶氏菌（0：9型）的目的基因片段;敏感性检测显示,乳样的检测灵敏度达50cfu／mL、纯化的布鲁氏菌DNA检测灵敏度达1．5pg,可重复性和稳定性十分理想。可见,该布鲁氏菌病病原PCR检测方法具有较高的特异性和敏感性,能为快速诊断布鲁氏菌病提供技术支撑。     

莱克多巴胺胶体金免疫层析快速检测试纸条的研制

应用胶体金免疫层析技术建立了一种快速检测莱克多巴胺的方法.采用柠檬酸钠还原法制备胶体金颗粒,标记莱克多巴胺单克隆抗体并喷于玻璃纤维上,莱克多巴胺偶联OVA抗原和羊抗鼠IgG分别结合于硝酸纤维膜上,依次将样品垫、胶体金垫、硝酸纤维素膜和吸水纸组装切割成莱兜多巴胺胶体金免疫层析快速检测试纸条.试验结果表明,陔快速检测试纸条的灵敏度为5 ng/mL,检测时间为5 min,批内和批问重复性为100%,假阳性率和假阴性宰均为0.     

Nanowire nanosensors for highly sensitive and selective detection of biological and chemical species

Boron-doped silicon nanowires (SiNWs) were used to create highly sensitive, real-time electrically based sensors for biological and chemical species. Amine- and oxide-functionalized SiNWs exhibit pH-dependent conductance that was linear over a large dynamic range and could be understood in terms of the change in surface charge during protonation and deprotonation. Biotin-modified SiNWs were used to detect streptavidin down to at least a picomolar concentration range. In addition, antigen-functionalized SiNWs show reversible antibody binding and concentration-dependent detection in real time. Lastly, detection of the reversible binding of the metabolic indicator Ca2+ was demonstrated. The small size and capability of these semiconductor nanowires for sensitive, label-free, real-time detection of a wide range of chemical and biological species could be exploited in array-based screening and in vivo diagnostics.     

副溶血性弧菌ELISA快速检测试剂盒的研制

副溶血性弧菌间接ELISA检测试剂盒的主要组成部件,应用试验结果表明该试剂盒检测低限达104 cfu/g,具有良好的稳定性和特异性;检测时间为8 h,大大缩短了检测时间,提高了检测效率,该试剂盒具有一定的实际应用价值.     

一种苯醚氰菊酯胶体金免疫快速检测试纸条的研制

通过制备苯醚氰菊酯半抗原,研制出一种能够检测蔬菜、水果中苯醚氰菊酯的胶体金免疫层析试纸条,检测限为1μg/kg,检测时间仅为15 min,假阳性率和假阴性率均为0,符合《农残办技术材料要求及审查程序》要求,该试纸条能够应用到基层实验室的大批量样本检测,具有实际意义。     

拟除虫菊酯类农药残留快速检测技术研究进展

文章阐述了拟除虫菊酯类农药在农副产品生产中的应用以及该类农药在食品中的残留现状,对拟除虫菊酯类农药残留常规检测分析方法和免疫分析方法进行了论述,指出这些分析方法在处理大量样品以及在高效、经济和快速检测方面仍存在缺陷,并对酶联免疫技术和免疫胶体金层析技术的快速检测研究进行了讨论。     

红色裸甲藻实时定量PCR快速检测方法的建立(英文)

    为建立快速、准确的赤潮藻鉴定和定量检测方法,以红色裸甲藻(Gymnodinium sanguineum)作为研究对象,将快速检测手段一实时荧光定量PCR(RFQ-PCR)技术应用于赤潮藻的种类鉴定中.首先以红色裸甲藻18S rDNA序列为靶区域.设计出适合用于RFQ-PCR技术的红色裸甲藻引物和TaqMan探针,并通过引物PCR验证确定其种特异性;进而应用实时荧光定量PCR方法建立红色裸甲藻快速检测方法.与显微镜计数方法比较,两者所获结果无显著性差异,且该方法的检测限远低于红色裸甲藻爆发赤潮时的藻密度,因此该方法可有效地应用于红色裸甲藻的检测,从而为红色裸甲藻赤潮的预警预测奠定基础.     

Visible-near infrared spectroscopy for detection of Huanglongbing in citrus orchards

This paper evaluates the feasibility of applying visible-near infrared spectroscopy for in-field detection of Huanglongbing (HLB) in citrus orchards. Spectral reflectance data from the wavelength range of 350-2500 nm with 989 spectral features were collected from 100 healthy and 93 HLB-infected citrus trees using a visible-near infrared spectroradiometer. During data preprocessing, the spectral data were normalized and averaged every 25 nm to reduce the spectral features from 989 to 86. Three datasets were generated from the preprocessed raw data: first derivatives, second derivatives, and a combined dataset (generated by integrating preprocessed raw data, first derivatives and second derivatives). The preprocessed datasets were analyzed using principal component analysis (PCA) to further reduce the number of features used as inputs in the classification algorithm. The dataset consisting of principal components were randomized and separated into training and testing datasets such that 75% of the dataset was used for training; while 25% of the dataset was used for testing the classification algorithms. The number of samples in the training and testing datasets was 145 and 48, respectively. The classification algorithms tested were: linear discriminant analysis, quadratic discriminant analysis (QDA), k-nearest neighbor, and soft independent modeling of classification analogies (SIMCA). The reported classification accuracies of the algorithms are an average of three runs. When the second derivatives dataset were analyzed, the QDA-based classification algorithm yielded the highest overall average classification accuracies of about 95%, with HLB-class classification accuracies of about 98%. In the combined dataset, SIMCA-based algorithms resulted in high overall classification accuracies of about 92% with low false negatives (less than 3%).     

断奶仔猪腹泻病原PCR鉴定及其药敏试验

江苏某养殖场断奶仔猪发生水样腹泻,使用庆大霉素治疗无效.通过采集其中3例腹泻病猪的肛拭子样品,接种LB肉汤培养6 h后,用PCR方法检测,结果发现仔猪腹泻由产肠毒素大肠杆菌(ETEC)引起.通过细菌分离获得60株细菌,PCR检测结果表明:其中2株为LT1+ST2型ETEC、1株为ST1型ETEC,且其菌毛型均为F18ac;药敏试验结果表明:这3株细菌均对呋喃妥因高度敏感,对多黏菌素中度敏感,对环丙沙星、新霉素低度敏感,对四环素、庆大霉素耐药,对左氟沙星、头孢唑林因不同菌株也有差异.另外,在肛拭子样品中还发现大量小袋纤毛虫,选用呋喃妥因和甲硝唑治疗,所有腹泻病猪均于5 d后康复.     

环介导等温扩增技术快速检测血液中白色念珠菌

目的 探讨环介导等温扩增法(loop-mediated isothermal amplification,LAMP)检测血液中白色念珠菌的可行性.方法 采用通用基因组DNA提取试剂盒提取血液中白色念珠菌DNA,应用LAMP方法进行扩增,采用浊度仪进行检测.结果 该方法能够检测出血液中白色念珠菌,而其它临床常见血流感染的...     

杭州市粮油类农产品真菌毒素快速检测与安全性评估

在真菌毒素传统检测方法基础上,建立并完善4类真菌毒素免疫亲和净化与荧光法(或HPLC)快速检测技术。应用真菌毒素快速检测技术对杭州市粮油类农产品进行抽样检测并作安全性评估。黄曲霉毒素总量和黄曲霉毒素B1的检测样本数为28个,检出率为25%;赭曲霉毒素A的检测样本数为48个,检出率为22.9%;玉米赤霉烯酮的检测样本数为49个,检出率为42.9%;呕吐毒素的检测样本数为39个,检出率为15.4%。4类真菌毒素的平均检出率约为30%左右。4类真菌毒素安全性评估结果为：黄曲霉毒素和玉米赤霉烯酮超标率最高,呕吐毒素安全性较好。检测结果表明,杭州市粮油类农产品真菌毒素污染广泛,部分真菌毒素超标比较严重,应该进一步加强对谷物及油料类农产品真菌毒素安全性监控工作。     

基于环式等温扩增的烟草青枯病病原菌快速检测方法

针对烟草青枯病的防控,开发快速、高效的病原菌检测方法是必要的。环式等温扩增(LAMP)是一种在等温条件下快速完成靶标基因扩增的新方法。将青枯病菌贵州分离株FQY4基因组序列(NCBI号:CP004013)与其他已发表菌株序列比对分析,确定编码鞭毛蛋白的fliC基因的保守区域可被选作检测靶标。根据LAMP原理以及靶标序列的特点,设计了一组由6条引物组成的环式等温扩增反应体系。结果表明:61℃条件下孵育45min,可完成对青枯病病原菌单菌落和带菌烟草叶片的检测,结果判定可以通过颜色变化被肉眼直接识别,也可以通过琼脂糖凝胶电泳检测。通过这种新方法,可以实现对青枯病菌菌落的快速鉴别,还可以用于对田间疑似带病烟草植株的快速检测。     

Three sensitive and reliable serological assays for detection of potato virus A in potato plants

Vegetative propagation of seed potato often allows passaging of viruses to seed tubers, resulting in significant yield losses and reduction of potato tuber quality. Thus, virus detection approach is crucial for effective virus management programs and the production of virus-free seed potatoes. Among the reported potato-infecting viruses, potato virus A (PVA) is considered as one of the most important viruses in potato-growing regions worldwide. This study prepared four hybridoma lines secreting PVA-specific monoclonal antibodies (MAbs) (2D4, 8E11, 14A6 and 16H10) using purified PVA virions as an immunogen. Western blotting results indicated that all the four MAbs reacted strongly and specifically with the putative capsid protein of PVA. Using these four MAbs, this study developed antigen-coated plate enzyme-linked immunosorbent assay (ACP-ELISA), Dot-ELISA and Tissue print-ELISA for detection of PVA infection in potato plants. The results indicated that PVA can be detected in crude tissue extracts from infected potato plants diluted up to 1:327680 (w/v, g mL^–1) by ACP-ELISA or up to 1:10240 by Dot-ELISA. The Tissue print-ELISA is the quickest and easiest approach among the three serological assays, and is more suitable for onsite large-scale potato screening programs. Further analyses of field-collected potato samples showed that the sensitivities and specificities of the three serological approaches were similar to those of RT-PCR in PVA detection and confirmed that PVA is currently widespread in Yunnan and Zhejiang provinces of China. Hence, the results strongly suggest that these highly sensitive serological approaches based on PVA-specific MAbs are useful and powerful for PVA-free seed potato production programs and PVA field surveys.     

A rapid,simple, and sensitive immunoagglutination assay with silica nanoparticles for serotype identification of Pseudomonas aeruginosa

An agglutination test based on colored silica nanoparticles (colored SiNps) was established to detect serotypes of Pseudomonas aeruginosa. Monodisperse colored SiNps were used as agglutination test carriers. The colored SiNps were prepared through reverse microemulsion with reactive dyes, sensitized with 11 kinds of mono-specific antibodies against P. aeruginosa, and denoted as IgG-colored SiNps. Eleven kinds of IgG-colored SiNps were individually mixed with P. aeruginosa on a glass slide. Different serotypes of P. aeruginosa could be identified by agglutination test with evident agglutination. The P. aeruginosa could be detected in a range from 3.6 × 10⁵ to 3.6 × 10¹² cfu mL^?1. This new agglutination test was confirmed to be a specific, sensitive, fast, easy-to-perform, and cost-efficient tool for the routine diagnosis of P. aeruginosa.     

光谱技术在肉类检测中的应用及研究进展

光谱技术是依据物体内部原子、分子等特定结构对电磁波有不同吸收特性的原理,对物体特定成分进行定性、定量的分析技术。对红外光谱技术和高光谱技术应用于肉类检测的检测原理、技术手段等进行归纳,从肉类溯源及品种检测、肉品品质(嫩度、新鲜度、持水率、大理石花纹等)检测、肉类安全、有毒物检测等方面综述了近红外光谱技术和高光谱技术在肉类检测中的研究现状,分析了光谱技术的存在问题,并对肉类检测的发展趋势进行展望。