基因芯片检测转基因油菜

在设计转基因油菜(Brassica napus)的基因芯片检测方法时，根据油菜中所转入的外源基因，选择了CaMV35S启动子、FMV35S启动子、Nos终止子、Bar基因、Barnase基因、Barstar基因、EPSPS基因、GOX基因、PAT基因和内源基因Fbp等设计了引物对与探针，并制备了寡核甘酸芯片，通过多重PCR对样品核酸进行扩增和荧光标记后，将PCR产物与芯片杂交，检测油菜样品中所含的外源基因。结果表明，实验有较好的特异性和重复性，在检测低含量的转基因油菜时灵敏度可达到0．5％。由于采用了多重PCR和芯片的多基因并行杂交的技术，一次可同时检测10个基因，在检测多品种混合的转基因油菜商品时具有独特优势。     

转红色荧光蛋白基因唐鱼肌肉中抗生素标记基因(NPTⅡ)检测和表达量分析

为了获得有特色的观赏鱼,本实验室在2003年将含有海葵红色荧光蛋白基因的表达载体(同时含有标记基因新霉素磷酸转移酶基因(NPTⅡ))转入唐鱼(Tanichthys albonubes)的受精卯,获得转红色荧光蛋白基因唐鱼,对其外源标记基因NPTⅡ的表达产物和存在时间进行分析,为评价转基因鱼的生物安全提供依据.本实验对转基因唐鱼和非转基因唐鱼肌肉中抗生素标记基因(NPTⅡ)进行PCR检测和NPTⅡ表达产物的免疫检测试剂条检测,结果显示,转基因唐鱼检测到NPTⅡ基因和表达产物,而非转基因唐鱼中均没检测到该基因和表达产物存在.同时在唐鱼死亡后(水温20～25℃),应用酶联免疫吸附测定法(ELISA)对死亡0 (鲜活肌肉)、24、48、72、96、120和144 h组的转基因唐鱼肌肉中NPTⅡ蛋白的含量进行定量检测,结果表明,转基因唐鱼鲜活肌肉中NPTⅡ蛋白在肌肉中的含量为9.12 ng/g,随着转基因唐鱼死亡时间增加肌肉中NPTⅡ蛋白含量逐渐减少,死亡96 h组转基因唐鱼肌肉中NPTⅡ蛋白已经接近为0.结果表明,转基因唐鱼肌肉中NPTⅡ蛋白在白然环境中容易降解,推测其对环境安全隐患相对较低.     

仿刺参体腔液补体类似物化学发光免疫检测

首次应用酶联化学发光免疫检测(Chemiluminesent Immunoassay,CLIA)技术测定仿刺参体腔液补体类似物AjC3和AjC4。羊抗人C3、C4抗体吸附到经过紫外线处理的聚苯乙烯管内,采用辣根过氧化物酶(HRP)标记抗体。过氧化氢和鲁米诺为辣根过氧化物酶的底物。捕获抗体包被最适浓度为1μg/ml,免疫反应20℃孵育2h达到平衡。HRP-IgC3、IgC4抗体复合物适宜稀释度为1:2000,HRP-IgC3I、gC4抗体复合物4℃下保存8d性能稳定,室温下5d内性能稳定。标准品浓度在0.1～10ng/ml范围内时与化学发光值之间具有良好的线性相关性,检测灵敏度为0.1ng/ml。结果表明应用酶联化学发光免疫检测技术能够检测到仿刺参体腔液中含有补体类似物,AjC3含量为6.58±1.4μg/ml,AjC4含量为0.67±0.3μg/ml。     

转基因棉花中新霉素磷酸转移酶(NPTⅡ)双抗体夹心ELISA定量检测方法的建立

为了建立高灵敏度定量检测转基因棉花(Gossypium sp.)中新霉素磷酸转移酶(NPTⅡ)双抗体夹心酶联免疫吸附方法(enzyme linked immunosorbent assay,ELISA),本研究以体外条件下制备NPTⅡ蛋白质为免疫原,制备兔(Lepus)抗NPTⅡ多克隆抗体为捕获抗体,小鼠(Mus musculus)抗NPTⅡ单克隆抗体为检测抗体,建立了双抗体夹心ELISA方法,以系列含量的NPTⅡ蛋白质作为标准品,建立标准曲线,对该方法各项指标进行验证,并对样品中所含NPTⅡ进行定量检测。结果表明,该双夹心ELISA对NPTⅡ检测范围为3.370~108.125 ng∕mL,最低检测限为1.97 ng/mL;准确性实验回收率为96.11%~104.69%;精密性变异系数为6.58%~7.33%;与非转基因棉花内源蛋白质及其他种类转基因蛋白质无交叉反应;应用此方法对苗期转基因棉植株各部位NPTⅡ表达量进行检测,发现有明显差异。该方法特异性强,灵敏度高,准确性、重复性和稳定性好,适用于检测转基因棉花中NPTⅡ含量,能够为今后转基因作物检测方法的建立及生物安全性评价等方面提供参考,具有良好应用价值和前景。     

中国转基因油菜的环境安全性分析

根据中国转基因油菜研究和环境释放的现状，对中国环境条件下转基因油菜的生存竞争能力、基因扩散风险以及对生物多样性影响等环境安全问题进行了分析。分析认为，中国是许多十字花科植物进化起源中心和生物多样性中心，生态环境类型复杂；转基因油菜的外源基因可以通过花粉向油菜（Brassica napus）、白菜（B．rapa）和芥菜（B．juncea）类植物扩散；中国转基因油菜的基因扩散风险高于其它作物．存中国，油菜的转基因技术相当成熟，油菜的转基因实验频次很高，涉及的基因种类繁多，进口的转基因油菜数量巨大，隐患不容忽视。在中国，转基因油菜的安全性管理和研究相当薄弱，检测和监测手段无法满足安全管理需求，这一现状必将阻碍中国转基困油菜的产业化进程，并对中国环境安全带来隐患。作者提出，加强转基因油菜的环境安全意识，加强中国转基冈油菜的安全管理及其措施的落实，加强转基因油菜检测和监测等技术平台的建设。     

利用菊花B病毒外壳蛋白特异片段进行多克隆抗体的制备与分析

菊花B病毒(CVB)是乙型线状病毒科(Betaflexiviridae)麝香石竹潜隐病毒属(Carlavirus)成员,在浙江杭白菊基地普遍存在。为了能够特异、快速、简便检测CVB,利用SWISS-MODEL分析CVB外壳蛋白(CP)的三维结构,选择暴露在CVB CP三维空间结构外部的片段,片段之间使用连接肽串联以提高柔性,重复4个片段,根据大肠杆菌密码子的偏爱性将其相应的DNA序列进行优化,将合成的特异DNA序列连接表达载体pET-28a(+),转化至Escherichia coli BL21(DE3)菌株,经IPTG诱导和Ni-NTA重力柱层析获得了纯化后大小约为14 kDa的融合蛋白;将其作为抗原免疫家兔制备抗血清,纯化获得相应抗体;对获得的抗血清和抗体进行酶联免疫吸附测定(ELISA)和蛋白免疫印迹(WB)检测。间接ELISA检测结果表明,512 000倍稀释的抗血清可检测到1 μg抗原。纯化后最终得到浓度为15 mg·mL^-1 的抗体,WB检测结果,1∶1 000稀释后的抗体可检测500 pg抗原,且能够特异性结合CVB CP蛋白。本研究制备的多克隆抗体为检测CVB提供了便利,也为后续CVB检测试纸条的开发提供了技术支撑。     

Construction of Canine parvovirus DNA Vaccine and Detection of Its Inoculated Mice

用PCR方法扩增犬细小病毒(Canine parvovirus，CPV) 貉分离株(PV/貉/CC/1/86)的VP2蛋白基因，并将其克隆入pMD18-T，命名为pTCPV，进行测序分析。结果除发现300G→S突变外，还发现32G→D突变。然后将PV/貉/CC/1/86 VP2蛋白基因克隆入真核表达载体pVAX1的CMV启动子的下游，构建了CPV核酸疫苗的真核表达质粒pVCPV。pVCPV转染BHK-21细胞能够表达CPV VP2蛋白，所表达的CPV VP2蛋白能够与抗CPV的阳性抗体发生特异性的抗原-抗体反应。用pVCPV免疫接种小鼠，用ELISA和微量中和试验检测免疫小鼠抗CPV抗体阳性，但是没有检测到抗CPV HI抗体； pVCPV免疫小鼠的脾淋巴细胞对特异性和非特异性抗原刺激均有明显的增殖。结果表明, pVCPV免疫接种小鼠能够诱导机体产生抗CPV的特异性体液免疫和细胞免疫。     

HPT-ELISA方法的建立及其在转基因水稻监测中的应用

本文改进了HPT-ELISA检测法,利用一种简便并且高效的微生物表达体系,将hpt基因的全编码序列克隆到原核表达质粒pGEX-KG上,在E.Coli菌株BL21(DE3)-pLys中进行诱导表达,获得了融合蛋白GST-HPT,经Thrombin凝血酶酶切过夜,再经过柱纯化后获得不含GST且具有生物活性的HPT纯蛋白,所得蛋白纯度>90%。MALDI-TOF-MS分析表明,HPT蛋白分子量为39.4KD。用HPT纯蛋白免疫家兔,制备了高效价的多克隆抗体,进而构建了双抗夹心酶联免疫检测方法,其灵敏度为0.31ng/ml。应用该HPT-ELISA方法,测定了不同生育期转Bt基因水稻植株中HPT蛋白的表达水平以及成熟期稻米中的HPT蛋白含量。结果表明,不同生育期转Bt基因水稻植株中HPT蛋白的表达量约为15.67~60.12ng/g.FW,转Bt基因稻米中HPT蛋白的含量为5.28ng HPT/g.FW,而在非转基因亲本的植株和稻米中均未检测到HPT蛋白。     

油菜籽中转基因抗草甘膦油菜籽的定量检测

根据转基因抗草甘膦油菜(Brassica napus)中的外源基因GOX和内源基因PEP设计引物和TaqMan荧光探针，使用ABIPRISM 7700定量PCR仪对进口油菜籽中转基因抗草甘膦油菜籽的含量进行了定量检测，建立了转基因抗草甘膦油菜籽参照样品GOX和PEP之间的Ct值之差△Ct与样品中转基因抗草甘膦油菜籽含量百分比之间的标准曲线和线性回归方程，并对3个未知油菜籽样品和3个油菜籽粕样品进行了检测，转基因抗草甘膦油菜成分含量分别为：12．62％、4．96％、6．78％、4．13％、12．81％和11．74％。     

长白猪Plin3、Plin5基因克隆及表达规律研究

脂滴包被蛋白3(Plin3)和脂滴包被蛋白5(Plin5)是细胞内脂滴包被蛋白(PAT)家族的成员,在脂滴合成方面具有重要作用。为探究Plin3和Plin5在长白猪中的序列和表达特征,利用PCR技术扩增该基因,采用生物信息学分析两者的序列特征,并利用实时荧光定量PCR技术检测其在长白猪11个不同组织中的表达特征。结果表明,长白猪Plin3序列全长1 403 bp,Plin5全长1 397 bp,两种蛋白二级结构均以α-螺旋为主,无规则卷曲次之,不存在跨膜结构,无信号肽结构,有多个磷酸化位点。检测两种基因在不同组织中的表达水平发现,Plin3在长白猪的11个组织中均有表达,其中在脾脏中的相对表达量显著高于其他组织(P<0.05),肝脏次之;Plin5在脂肪组织中的相对表达量显著高于其他组织(P<0.05),而在大肠和小肠中不表达。本研究为进一步探究长白猪Plin3和Plin5在脂质代谢中的作用机制提供了理论依据。     

Application of immunoaffinity column as cleanup tool for an enzyme linked immunosorbent assay of phosphinothricin-N-acetyltransferase detection in genetically modified maize and rape

We have developed a new immunoassay method to detect genetically modified (GM) maize and rape containing phosphinothricin-N-acetyltransferase (PAT). PAT encoded by Bialaphos resistance gene (bar) was highly expressed in soluble form in Escherichia coli BL21(DE3) and purified to homogeneity by Ni2+ affinity chromatography. A simple and efficient extraction and purification procedure of PAT from GM maize and rape was developed by means of the immunoaffinity column (IAC) as a cleanup tool. Purified polyclonal antibodies against PAT was produced and coupled covalently to CNBr-activated Sepharose 4B. Both the binding conditions and elution protocols were optimized. The IAC was successfully employed to isolate and purify the PAT from the various tissues of GM maize (Bt11 and Bt176) and rapes (MS1/RF1 and MS8/RF3). Enzyme linked immunosorbent assay (ELISA) procedures were established further on to measure the PAT protein. GM maize cannot be differentiated from non-GM maize by ELISA. But IAC-ELISA allowed 0.5% GMOs to be detected in MS1/RF1 and MS8/RF3 and 10% GMOs to be detected in Bt11 and Bt176, which makes this method an acceptable method to access PAT protein in GM rapes and maize.     

磺胺二甲氧嘧啶单克隆抗体的制备及其免疫学特性鉴定

用重氮化法将SDM(磺胺二甲氧嘧啶)偶联于载体蛋白BSA和OVA,合成免疫原BSA-SDM和包被原OVA-SDM,并用紫外扫描(UV)、SDS-PAGE进行鉴定;用BSA-SDM免疫BALB/C小鼠,间接ELISA和阻断ELISA选择细胞融合备用鼠;应用杂交瘤技术建立分泌SDM mAb细胞株,用体内诱生腹水法制备SDM mAb;对SDM mAb的效价、亲和性、敏感性和特异性等免疫学特性进行鉴定。结果表明,BSA-SDM人工抗原制备成功,分子结合比约为1∶12.1;筛选出1B43、D9、4E1共3株敏感特异的杂交瘤细胞,间接ELISA效价细胞培养上清分别为1∶3.2×102、1∶5.12×102、1∶8.1×102,腹水分别为1∶2.56×105、1∶2.56×1051、∶5.12×105,4E1亲和常数(Ka)为1.25×1010L/mol;4E1株对SDM的IC50为16.64ng/ml,与磺胺-6-甲氧嘧啶交叉反应率为5%,与其他磺胺类药物无交叉反应性。本试验获得了抗SDM高价、敏感、特异的mAb,可用于SDM残留检测的免疫学试验。     

特布他林杂交瘤细胞株的建立及其单克隆抗体制备与鉴定

分别通过1,4丁二醚法和EDC法将特布他林偶联于载体蛋白BSA和OVA上,用BSA-TBL免疫BALB/c小鼠,经过3次免疫后,OVA-TBL包被后用间接ELISA和阻断ELISA选择细胞融合备用鼠,选择高效价、高敏感性和高特异性的小鼠进行抗原进行冲击免疫;无菌手术取其脾细胞与骨髓瘤细胞融合建立分泌TBL单克隆抗体的杂交瘤细胞株;采用体内诱生腹水法制备TBL mAb,并对TBL mAb的效价、敏感性和特异性等免疫学特性进行鉴定。结果显示,免疫的6只小鼠血清抗体效价均达到10-4;融合后筛选出4C08-G5和3H3-A02共2株敏感特异的杂交瘤细胞,其细胞培养上清液效价分别为1∶800和1∶1600,腹水效价分别为1∶2.56×105和1∶1.02×106;4C08-G5株分泌的抗体对TBL的IC50为5.25ng/ml,与瘦肉精、莱克多巴胺等其他β2激动剂交叉反应性小于3%。本试验获得了抗TBL mAb,为TBL残留免疫检测方法的建立奠定了坚实的基础。     

Development of an ELISA for the detection of the residues of the insecticide imidacloprid in agricultural and environmental samples

A competitive enzyme-linked immunosorbent assay (ELISA) for the chloronicotinyl insecticide imidacloprid was developed using a polyclonal antibody produced against a hapten conjugated through the imidazolidine to keyhole limpet hemocyanin. In the standard curve of imidacloprid, an IC(50) of 17.3 ng/mL was obtained using a competitive heterologous system at pH 10. Very low cross-reactivity was found for some structurally related compounds including the insecticide thiacloprid. The high cross-reactivity with a metabolite containing the carbonyl group in the imidazolidine moiety suggests the involvement of its polarity and stereochemical fitness in forming the antibody--antigen complex. The effects of various assay conditions, including organic solvents, detergent content, salt concentration, and pH on the sensitivity were evaluated. High-performance liquid chromatography was run for comparison to validate the ELISA with fortified water samples, the correlation being 0.997-0.998 (n = 15) with a slope of 1.10--1.38. The ELISA turned out to be a convenient tool for monitoring imidacloprid residues in agricultural and environmental samples.     

西马特罗杂交瘤细胞株的建立及其单克隆抗体制备和鉴定

用重氮化法将牛血清白蛋白（BSA）和卵清蛋白（OVA）分别与西马特罗（CIM）偶联作为免疫原或包被原,用BSA-CIM免疫BALB/c小鼠,经过3次免疫后,OVA-CIM包被后用间接ELISA和阻断ELISA选择细胞融合备用鼠,选择高效价、高敏感性和高特异性的小鼠进行抗原超强免疫;取脾细胞应用杂交瘤技术与骨髓瘤细胞建立分泌CIM单克隆抗体（Monoclonal antibody,mAb）的杂交瘤细胞株;用体内诱生腹水法制备CIM mAb,对CIM mAb的效价、敏感性和特异性等免疫学特性进行鉴定。结果显示免疫的6只小鼠血清抗体效价均达到10-3;融合后筛选出3B11-H4、2A11-G11和4F5-F11共3株敏感特异的杂交瘤细胞,其细胞培养上清液效价分别为1∶800、1∶1600和1∶1600,腹水效价分别为1∶2.56×106、1∶1.02×107和1∶2.56×107,3B11-H4株对CIM的IC50为040ng/ml,与瘦肉精、莱克多巴胺等其他β2激动剂交叉反应性小于02%。本试验获得了高效价、敏感、特异的抗CIM mAb,为CIM残留ELISA检测试剂盒和试纸条的建立奠定了坚实的基础。     

A 50 kDa maize gamma-zein has marked cross-reactivity with the almond major protein

Cross-reactivity of antibodies against almond major protein (AMP, a legumin), the major almond allergen, with cereal proteins may cause problems in detecting almond contaminants in cereal products when antibody-based assays are used. Rabbit polyclonal IgG antiserum produced against AMP was used to test cross-reactivity with protein extracts from maize, a cereal commonly found in breakfast and snack foods. Gradient SDS-PAGE followed by Western blotting was performed, and two cross-reactive proteins were detected by chemiluminescence. A fraction of maize proteins purified by elution from an IgG anti-AMP affinity column followed by electrophoreseis and immunoblotting showed a high degree of cross-reactivity with a minor 50 kDa protein of maize, as well as low cross-reactivity with the 27 kDa gamma-zein. The 50 kDa cross-reactive protein was identified as the 50 kDa gamma-zein by immunoreaction with anti-50 kDa gamma-zein antiserum. Notably, the 50 kDa maize gamma-zein also reacted with IgE from pooled human sera from patients with self-reported severe almond allergies. The high immunoreactivity of the 50 kDa gamma-zein should be considered in maize quality improvement programs, and such notable cross-reactivity is of relevance in the design of antibody-based assays for almond allergen detection.     

New approach to immunochemical determinations for triclopyr and 3,5,6-trichloro-2-pyridinol by using a bifunctional hapten,and evaluation of polyclonal antiserum

The present work describes the design and synthesis of the structurally unique hapten, "bifunctional hapten", to produce a group-specific polyclonal antiserum to triclopyr and 3,5,6-trichloro-2-pyridinol. A bifunctional hapten was designed and synthesized by conjugating commercially available Nepsilon-2,4-dinitrophenyl (DNP)-L-lysine to triclopyr, and then coupling this to carrier proteins such as bovine serum albumin (BSA). The synthesized bifunctional hapten greatly raised the antiserum titer in comparison with that of the conventional hapten, triclopyr. Antiserum with a sufficiently high titer to provide the determinations of targeted compounds was obtained only 63 days after the primary immunization. The obtained antiserum showed the highest affinity to triclopyr (IC(50) = 3.5 nM) and 3,5,6-trichloro-2-pyridinol (IC(50) = 5.1 nM) in homologous ELISA. The cross-reactivities to various agrochemicals and some chlorinated phenolic compounds were determined. Significant cross-reactivity was found to the herbicide 2,4,5-T. The antiserum reacted to both triclopyr and its metabolite. Assay sensitivity was evaluated for effects of various assay conditions, including pH value and concentrations of organic solvents and detergents. Under optimized assay conditions, the quantitative working range of triclopyr ELISA was from 0.1 to 5.2 ng/mL with a limit of detection (LOD) of 0.037 ng/mL, and an IC(50) of 0.72 ng/mL. On the other hand, the quantitative working range of 3,5,6-trichloro-2-pyridinol ELISA was from 0.13 to 6.0 ng/mL with a LOD of 0.052 ng/mL, and an IC(50) of 0.95 ng/mL. Water samples fortified with triclopyr or its metabolite at 1, 5, and 10 ng/mL were directly analyzed without extraction and cleanup by the proposed ELISA. The mean recovery was 101.6%, and the mean coefficient of variation (CV) was 7.1% in the case of the triclopyr ELISA. In the case of the 3,5,6-trichloro-2-pyridinol ELISA, the mean recovery was 99.8%, and the mean CV was 9.5%. The proposed ELISA turned out to be a powerful tool for monitoring of residual triclopyr or 3,5,6-trichloro-2-pyridinol in water samples at trace level.     

伏马菌素B1人工抗原的合成及鼠源多克隆抗血清的制备

本研究合成并鉴定伏马菌素B₁(FB₁)人工抗原,通过动物免疫制备敏感性高、特异性好的鼠源FB₁多克隆抗血清。采用碳二亚胺(EDC)法将FB₁分别与载体蛋白BSA和OVA偶联,合成免疫抗原FB₁-BSA和检测抗原FB₁-OVA,经鉴定后,分别按10和30μg/只的剂量免疫BALB/c小鼠,共免疫4次,每次间隔3周,最后1次免疫30d后,断尾采血,制备多抗血清。利用间接ELISA方法测定抗血清效价,间接竞争ELISA测定敏感性和特异性。结果表明,免疫的6只小鼠效价均达1∶104以上,3号小鼠多抗血清敏感性最好,半数抑制浓度IC₅₀为61.3ng/ml,且具有良好的特异性。本试验成功合成了FB₁人工抗原,并制备了敏感性高、特异性好的鼠源多克隆抗体血清,为FB₁单克隆抗体制备及其免疫学快速检测方法的建立奠定了基础。     

A highly specific enzyme-linked immunosorbent assay for the detection of Cry1Ac insecticidal crystal protein in transgenic WideStrike cotton

A highly selective enzyme-linked immunosorbent assay (ELISA) has been developed for the quantitative detection of the Cry1Ac protein expressed in transgenic cotton. Two Cry1Ac-specific monoclonal antibodies (MAb), Kbt and 158E6, were developed and selected to form a sandwich format ELISA. The MAb Kbt was used as a capture antibody, and 158E6 was conjugated with horseradish peroxidase and served as a detection antibody. The assay was optimized and validated with different cotton matrices. Tissues were extracted with phosphate-buffered saline containing 0.05% Tween 20 and 1% polyvinylpyrrolidone. The extract was then treated with trypsin to truncate full-length Cry1Ac into the core toxin for quantitation. The resulting assay has good accuracy and precision with a validated limit of quantitation ranging from 0.1 to 0.375 mug/g dry weight of cotton tissues. This assay is highly specific for Cry1Ac protein and has no cross-reactivity with the nontarget proteins tested such as Cry1Ab and Cry1F.