应用复合引物扩增大肠杆菌肠毒素基因的研究

以两对合成的不同寡核苷酸引物通过聚合酶链反应（ＰＣＲ）、扩增肠毒素大肠杆菌（ＥＴＥＣ）不耐热肠毒素（ＬＴ）和耐热肠毒素（ＳＴ）基因；两对引物从ＥＴＥＣＬＴ和ＳＴ基因中分别扩增出３１４ｂｐ，２３７ｂｐ的ＤＮＡ片段，均能与相应的ＬＴ和ＳＴ基因探针杂交。ＬＴ扩增产物（３１４ｂｐ）和ＳＴ扩增产物（２３７ｂｐ）分别和ＳｍａⅠ和ＨｉｎｃⅡ酶切后，产生１９０ｂｐ和１２４ｂｐ，１４７ｂｐ和９０ｂｐ的ＤＮＡ片段。同一扩增反应中应用ＬＴ和ＳＴ复合引物进行扩增，３种基因型ＬＴ、ＳＴ和ＬＴＳＴＥＴＥＣ从样品中鉴定出。１０９份动物腹泻粪样分别用ＰＣＲ，核酸杂交和ＥＬＩＳＡ进行测定，结果表明，ＰＣＲ是最为灵敏和快速的测定ＥＴＥＣ的方法。     

用PCR快速检测对虾白斑病病毒DNA

用ＰＣＲ技术快速检测对虾白斑病病毒。引物１４６Ｆ１和１４６Ｒ１用于扩增病毒ＤＮＡ中１４４７ｂｐ的片断，引物１４６Ｆ２和１４６Ｒ２用于扩增１４４７ｂｐ片断中长９４１ｂｐ的一段。经２００多个样品分析结果显示，该方法能可靠地检测到患病对虾体内的白斑病毒ＤＮＡ。文中同时讨论了近年来白斑病流行的新动向。     

牛β—酪蛋白基因上游调控序列PCR扩增及克隆

采用蛋白酶Ｋ法从母牛肝中提取染色体ＤＮＡ,将其纯化后作为ＰＣＲ扩增模板。以引物设计软件从牛β－酪蛋白基因上游６００ｂｐ至第１个外显子设计引物,引物长度１９ｎｔ,跨度６３７ｂｐ。扩增产物电泳结果显示,在分子量Ｍａｒｋｅｒ６５７ｂｐ带附近,出现一明显亮带,这一结果与设计产物大小基本一致。用低温冷冻法纯化ＰＣＲ产物,煮沸裂解法提取载体ｐＢｌｕｅｓｃｒｉｐｔⅡＫｓ＋质粒,ＥｃｏＲＶ酶切质粒ＤＮＡ,Ｔ４ＤＮＡ连接酶连接ＰＣＲ扩增片段和质粒ＤＮＡ。将重组质粒ＤＮＡ转化到ＪＭ１０１大肠杆菌中,经筛选、酶切、测序鉴定,结果表明所克隆的片段为牛β－酪蛋白基因上游调控序列。     

用PCR和探针杂交法检测鸡败血霉形体

根据鸡败血霉形体ｆＭＧ－２核酸片断序列,设计合成了１对２５ｂｐ寡核苷酸引物,对鸡败血霉形体基因组ＤＮＡ进行扩增,均获得预期的７３２ｂｐ扩增产物,检测灵敏度为１ｂｐ;参考菌株ＤＮＡ无扩增。回收纯化琼脂糖电泳凝胶中的扩增产物,ＤＩＧ随机引物法合成核酸探讨,Ｄｏｔ－ｂｌｏｔ杂交试验,鸡败血霉形体呈阳性,检测灵敏度为１００ｐｇ;其他为阴性。对自然发病鸡群检测进一步表明,建立的ＰＣＲ和探针杂交法具有高度的灵     

用PCR快速地虾白斑病病毒DNA

用ＰＣＲ技术快速检测对虾白斑病病毒。引物１４６Ｆ１和１４６Ｒ１用于扩增病毒ＤＮＡ中１４４７ｂｐ的片断,引物１４６Ｆ２和１４６Ｒ２用于扩增１４４７ｂｐ片断中长９４１ｂｐ的一段。经２００多个样品分析结果显示,该方法能可靠地检测到患病对虾体内的白斑病毒ＤＮＡ。文中同时讨论了近年来白斑病流行的新动向。     

制备K700bp成探针与美意和平湖两品系西蜂RAPD—PCR扩增产物及它们基因 …

Ｋ７００ｂｐ是高产蜜西蜂引物Ｋ（５’－ＣＧＧＣＣＣＣＴＧＣ－３’），通过ＲＡＰＤ－ＰＣＲ扩增出来的一个特有ＤＮＡ片段。然后将Ｋ７００ｂｐ制备成探针再与高、低产蜜西蜂的ＰＣＲ产物及它们的基因组进行杂交。结果Ｋ７００探针只与高产蜜西蜂的ＰＣＲ产物及其基因组杂交，证明Ｋ７００ｂｐ确实是高产蜜西蜂的一个特有ＤＮＡ片段。     

制备K700bp成探针与美意和平湖两品系西蜂RAPD-PCR扩增产物及它们基因组DNA分子杂交的研究

Ｋ７００ｂｐ 是高产蜜西蜂引物Ｋ（５’－ ＣＧＧＣＣＣＣＴＧＣ－ ３’） ，通过ＲＡＰＤ－ ＰＣＲ 扩增出来的一个特有ＤＮＡ 片段。然后将Ｋ７００ｂｐ 制备成探针再与高、低产蜜西蜂的ＰＣＲ 产物及它们的基因组进行杂交。结果Ｋ７００探针只与高产蜜西蜂的ＰＣＲ 产物及其基因组杂交，证明Ｋ７００ｂｐ 确实是高产蜜西蜂的一个特有ＤＮＡ 片段。     

应用特异性引物检测中国不同地区旋毛虫DNA

根据Ｊｅａｎ－Ｄｕｐｏｕｙ－Ｃａｍｅｒ所报道１．７ｋｂ基因序列而设计合成的引物,对中国九个地区的旋毛虫株的肌组织旋毛虫ＤＮＡ进行了聚合酶链反应（ＰＣＲ）。扩增产物经琼脂糖凝胶电泳分析,可见中国猪源旋毛虫均扩增出特异性的６０２ｂｐ和２３０ｂｐ大小的ＤＮＡ条带,而中国犬源和猫源以及正常对照肌组织ＤＮＡ均未扩增出特异性片段。本法对中国猪源旋毛虫可检测到０．０２条旋毛虫ＤＮＡ,具有高度的特异性和敏感性。     

应用随机扩增多态性DNA技术对产气荚腊梭菌的基因分型

采用随机扩增多态性ＤＮＡ（ｒａｎｄｏｍｌｙ ａｍｐｌｉｅｄ ｐｏｌｙｍｏｒｐｈｉｃＤＮＡ,ＲＡＰＤ）技术对产气英膜梭菌进行ＰＣＲ扩菌。结果,产气英膜梭菌Ａ、Ｂ、Ｃ、Ｄ４个型均可扩增出约４３０ｂｐ的条带,Ｂ、Ｃ型还扩增出约２１０ｂｐ的条带,Ｂ、Ｄ型还扩增出约１２１０ｂｐ的条带,Ａ型还扩增出约２４０ｂｐ和６９０ｂｐ的条带,各型之间的条带差别明显。     

PRV特异性糖蛋白gp50基因片段的克隆探针制备

在ＢＨＫ２１细胞中增殖伪狂犬病病毒（ＰＲＶ），提纯ＰＲＶＤＮＡ，选编码特异性糖蛋白ｇｐ５０基因中的２６２ｂｐ片段进行ＰＣＲ扩增。扩增产物经ＫｐｎⅠ和ＳａｌⅠ双酶切后，将２２２ｂｐ片段与质粒ｐＵＣ１９连接构成重组子ｐＵＰ。通过转化大肠杆菌ＪＭ８３、Ａｍｐｒ和α互补效应筛选后，扩增、提纯重组子ｐＵＰ，用ＫｐｎⅠ和ＳａｌⅠ酶切，电泳回收克隆的２２２ｂｐ片段。用光敏生物素标记２２２ｂｐ片段和重组子ｐＵＰ制备的探针，分别检出４６．８ｐｇ和９３．６ｐｇ的ＰＲＶＤＮＡ，且ｐＵＰ探针只与ＰＲＶ呈杂交阳性反应，与ＨＳＶ－１、ＨＳＶ－２及ＣＭＶ呈阴性反应。     

Polymerase chain reaction amplification for direct detection of chicken anemia virus DNA in tissues and sera.

Direct detection of chicken anemia virus (CAV) DNA in tissues and sera was investigated by a polymerase chain reaction (PCR) assay. Using a pair of primers constructed to amplify the coding sequence of the CAV DNA genome, the PCR assay was shown to be extremely sensitive, being able to detect 1 fg of CAV replicative form DNA. The oligonucleotide primers used for the PCR yielded 583 base-pair (bp) amplified product, which was sized by ethidium bromide-agarose gel electrophoresis. Tissue samples from seven cases of suspected chicken infectious anemia were obtained for CAV isolation. DNA extracted from the homogenized suspension of pooled tissues of each case was analyzed by the PCR assay. Results showed that five of the seven cases were positive for CAV DNA by PCR, whereas CAV was isolated from four cases only. The PCR assay also detected CAV DNA in two of 37 serum samples from disease-free chickens. The specificity of PCR was confirmed by chemiluminescence dot-blot analysis of the amplified products.     

犬附红细胞体PCR检测方法的建立

目的 步建立犬附红细胞体PCR检测方法。方法 据已发表的附红细胞体基因序列,设计了一对特异性引物,以犬附红细胞体基因组DNA和附红细胞体可疑病犬样品DNA为模板,聚合酶链式反应（PCR）扩增,扩增产物经克隆测序分析。结果 CR扩增产物大小为541bp,序列分析表明与GenBank数据中发表的序列一致,表明这套引物成功扩增出目的基因序列,但正常犬血样品DNA和弓形虫、伊氏锥虫、吉氏巴贝斯虫、犬细小病毒、犬瘟热的DNA样品都不能扩增出目的基因片段。结论 研究建立的PCR方法可以用于犬附红细胞体的检测,为犬附红细胞体病的诊断及分子流行病学的调查提供了新的手段。     

禽偏肺病毒地高辛核酸探针的制备与应用

根据GenBank中已经发表的B亚型禽偏肺病毒F基因的保守序列设计并合成1对引物,利用RT—PCR扩增出1条与目的片段大小一致的725bp基因片段,回收、纯化PCR产物,用地高辛标记,制备出地高辛标记的aMPV核酸探针。特异性检测结果表明,该探针能与aMPV核酸发生特异性杂交,而与H9N2亚型AIV、NDV、IBV、ORT和E．coil的核酸杂交反应均为阴性;敏感性检测结果表明,该探针对aMPV的最低检出量为5Pg。应用制备的探针对山东省不同地区的605份商品肉鸡和122份商品肉鸭进行了核酸探针检测,阳性检出率分别为36．59％和34．51％。本试验制备的aMPV地高辛探针特异性强、敏感性好,对样品的检测结果表明山东省部分地区的商品肉鸡、肉鸭中普遍存在aMPV感染。     

鹅血液基因组DNA的简单快速提取方法研究

本研究针对家禽血液红细胞有细胞核的特点,研究适合鹅血液基因组DNA的廉价、简便、快速的DNA提取方法,并为其它禽(鸟)类相关操作提供参考。通过裂解细胞,利用简便快速的操作方法将蛋白质和核酸分离,去除杂质,沉淀核酸,获得大量基因组DNA,并通过基因扩增检测其质量和效果。该方法提取的基因组DNA电泳检测条带明量,无拖尾,含量及纯度均较高,能够用于分子生物学实验研究。与传统的酚-氯仿DNA抽提方法相比,本实验建立的血液基因组DNA提取方法具有成本低、操作步骤简便和快速的特点,特别是对大量样品的提取更为实用。     

羊流产衣原体主要外膜蛋白基因的克隆与序列分析

将自行分离、传代培养的内蒙古地区山羊流产衣原体按常规方法分离纯化，提取衣原体基因组DNA作为模板，按照国外发表的衣原体主要外膜蛋白（MOMP）基因两端序列设计合成一对引物，用PCR方法扩增出－1.17Kb的DNA片段。利用引物上预先设计的限制性内切酶位点，将扩增片段经限制性内切酶切割后连接到pUC19质粒相应位点上，转化大肠杆菌DH5α，筛选重组子。经PCR检测和内切酶分析鉴定含MOMP基因的重组子质粒。对克隆处段进行全序列分析，结果证明得到MOMP全编码序列的基因克隆。本株衣原体MOMP编码区由1170个核苷酸组成。序列比较发现本株衣原体的MOMP基因与国外的羊流产衣原体S26／3株的MOMP基因完全相同，与B577株的MOMP基因仅有一个核苷酸的同义变异。     

PCR技术在鼠金黄色葡萄球菌检测中的初步研究

根据已公布的金黄色葡萄球菌耐热核酸酶nuc基因的序列 ,设计并合成一对特异性的引物 ,利用PCR技术扩增nuc基因片段。对金黄色葡萄球菌和其他非金黄色葡萄球菌菌株抽提的DNA进行扩增。结果金黄色葡萄球菌PCR产物出现 6 6 8bp的特异性DNA扩增片段 ,而其他非金黄色葡萄球菌未出现扩增片段 ,证实了合成的引物对金黄色葡萄球菌具有特异性。将抽提的金黄色葡萄球菌DNA进行系列稀释 ,测定此PCR体系的敏感性。结果显示 ,该PCR体系能检出 3pg金黄色葡萄球菌DNA ,且从抽提DNA到PCR扩增及电泳结束仅需 4h。因此 ,研究所建立的扩增耐热核酸酶nuc基因检测鼠金黄色葡萄球菌的PCR方法 ,具有快速、可靠、敏感和特异的特点 ,可用于临床样品和金黄色葡萄球菌感染时的检测 ,适合应用于实验大小鼠的监测     

Detection of canine parvovirus in fecal samples using loop-mediated isothermal amplification.

Loop-mediated isothermal amplification (LAMP) is a novel, sensitive, and rapid technique for detection of genomic DNA. The end-product of the technique is a white precipitate of magnesium pyrophosphate that is visible without the use of gel electrophoresis. The LAMP method was applied to the detection of canine parvovirus (CPV) genomic DNA. A set of 4 primers, 2 outer and 2 inner, were designed from CPV genomic DNA targeting the VP2 gene. The optimal reaction time and temperature for LAMP were determined to be 60 minutes and 63 degrees C. On the basis of results for 50 canine fecal samples using polymerase chain reaction (PCR) analysis as the gold standard, the relative sensitivity of LAMP was 100% and the relative specificity was 76.9%. The detection limit of the LAMP method was 10(-1) median tissue culture infective doses (TCID50)/ml, compared with 10 TCID50/ml for PCR analysis. In addition to the advantage resulting from visual detection of the end product, the LAMP method is very rapid, requiring only 1 hour to complete. This assay would be a viable alterative to PCR analysis for diagnosis of CPV infection in dogs. The LAMP method holds promise for use as a diagnostic assay for CPV detection in a clinical setting.     

A polymerase chain reaction assay for the detection of Leptospira spp. in bovine semen.

A rapid and specific method for the detection of pathogenic Leptospira spp. in bovine semen using the polymerase chain reaction (PCR) is described. The primers used were derived from an EcoR1/BamH1 fragment that hybridized strongly to chromosomal DNA from the hardjobovis serovar. Three different extraction methods were evaluated in this study: phenol-chloroform extraction method, proteinase K (PK) in 1% SDS, followed by phenol-chloroform, and phenol-chloroform followed by 1% cetyltrimethylammonium bromide (CTAB). A PCR product of approximately 500 base pairs (bp) in length was obtained when DNA from pure Leptospira culture was used as a template for PCR, regardless of the DNA extraction method used. The product was consistent with that predicted from the gene sequence. However, in semen seeded in vitro, as well as in semen from infected bulls, a PCR product was obtained only when the leptospiral DNA was extracted from the specimen using the CTAB method. In contrast, other methods used for DNA extraction did not generate suitable templates for the PCR procedure. This is the first PCR protocol developed to detect Leptospira in bovine semen. The PCR protocol provided a direct and unequivocal demonstration that Leptospira can be detected in semen of infected animals. The CTAB method was also used successfully in detecting Leptospira in the urine of infected animals. The PCR procedure was shown to be more sensitive than either the fluorescent antibody test (FAT) or culture for detecting the organism in urine.