加工产品中转基因玉米Bt11成分实时荧光PCR定量(性)检测

实验在玉米自身基因和外源基因的边界序列之间设计了具有品种和品系特异性的引物和探针 ,并以实时荧光PCR技术 ,建立了加工产品中转基因玉米Bt1 1成分品系鉴定检测和定量检测的方法。实验对加热条件和时间对检测转基因成分的影响作了探讨 ,并检测了部分市售食品和饲料。检测结果发现 ,加热时间温度越高、时间越长 ,对转基因成分定量检测的影响越大 ;在所检测的样品中可以检测出转基因玉米Bt1 1成分 ,有些样品还同时检出其他转基因成分。本研究实验建立的方法 ,可以用于加工产品中转基因成分的定量检测 ,也可以用于定性检测 ,或作为常规PCR定性检测后的确证实验方法。     

不结球白菜种质资源对TuMV的抗性鉴定与评价

分别利用苗期人工接种鉴定及ELISA检测方法,对127份不结球白菜种质资源进行芜菁花叶病毒(TuMV)的抗性鉴定。结果显示,苗期人工接种鉴定的病情指数(DI)分布在3.55~95.68之间,不同种质间表现出较大的抗性差异。不同抗性级别的次数分布图基本符合正态分布,略向感病区域偏离。基于病情指数的聚类分析结果与抗病性分级基本一致。通过苗期鉴定共筛选获得高抗TuMV的不结球白菜种质6份,抗病种质13份,其主要农艺性状表现出一定的多样性。其中叶面皱缩和具有刺毛的抗病材料所占比例较高,可能与TuMV抗性存在一定的相关性。ELISA检测结果显示,117份供试种质的P/N值分布在3.10~25.37之间,不同种质间表现出病毒含量的差异,但与DI值未呈现明显相关性,可作为抗病材料筛选的辅助指标。     

Isothermal amplification detection of nucleic acids by a double-nicked beacon

Isothermal and rapid amplification detection of nucleic acids is an important technology in environmental monitoring, foodborne pathogen detection, and point-of-care clinical diagnostics. Here we have developed a novel method of isothermal signal amplification for single-stranded DNA (ssDNA) detection. The ssDNA target could be used as an initiator, coupled with a double-nicked molecular beacon, to originate amplification cycles, achieving cascade signal amplification. In addition, the method showed good specificity and strong anti-jamming capability. Overall, it is a one-pot and isothermal strand displacement amplification method without the requirement of a stepwise procedure, which greatly simplifies the experimental procedure and decreases the probability of contamination of samples. With its advantages, the method would be very useful to detect nucleic acids in point-of-care or field use.     

黄牡丹八个居群的Giemsa C-带比较研究

应用ＢＳＧ方法对黄牡丹（Ｐａｅｏｎｉａ ｄｅｌａｖａｙｉ ｖａｒ．ｌｕｔｅａ）８个居群的Ｇｉｅｍｓａ Ｃ－带进行了比较研究。８个居群的所有染色体都在着丝点附近显示出了Ｃ－带,所有染色体的长臂上都没有显示Ｃ－带,而短臂上的Ｃ－带数量和位置在居群之间表现出了一定的差异。花甸凡居群手第二、第三、第四和第五对染色体显示端带;卓干山居群的第一、第三、第四和第五对染色体的短臂上没有显示Ｃ－带。在所研究的８个居     

肺炎支原体感染鼠P1特异抗原的动态检测

通过实验动物模型探讨肺炎支原体感染动物肺泡灌洗液中特异抗原检出率的动态变化,为肺炎支原体感染的临床诊断提供理论依据。小鼠经鼻自然感染肺炎支原体,分别采集感染后不同时间点小鼠的支气管灌洗液,应用量子点标记肺炎支原体P1蛋白抗体,直接免疫荧光法检测感染鼠肺泡灌洗液中肺炎支原体P1特异抗原,同时通过PCR检测肺组织肺炎支原体DNA及肺组织病理切片观察肺部炎性变化确定小鼠感染。结果显示,感染鼠肺炎支原体特异抗原在感染后第3天检出阳性率为75%,第7天达高峰为83%,之后随病程延长,抗原检测的阳性率逐渐下降,在感染后第14、21天检出阳性率分别为58%和25%。肺炎支原体特异抗原在感染早期检出率高。应用量子点标记肺炎支原体P1蛋白抗体,直接免疫荧光法检测肺炎支原体特异抗原可应用于肺炎支原体感染的早期诊断。     

Amperometric biosensor based on enzymes immobilized in hybrid mesoporous membranes for the determination of acetylcholine

Acetylcholine sensor is successfully prepared by using immobilized enzymes, i.e., acetylcholinesterase and choline oxidase within separate hybrid mesoporous silica membranes with 12 nm pore diameter (F127M). The measurement was based on the detection of hydrogen peroxide produced by two sequential enzyme reactions. The determination range and the response time are 6.0–800 μM and within approximately 3 min, respectively. The sensor is very stable compared to free enzymes and 80% of the initial response was maintained even after storage for 80 days. These results show that two enzymes are successfully immobilized and well stabilized, and at the same time, two sequential enzyme reactions efficiently proceed within the separate hybrid mesoporous membranes. Further, we studied the possible detection of organophosphorus pesticides in terms of the inhibition of acetylcholinesterase activity, i.e., the decrease of current response, and demonstrated that the nanomolar concentrations of pesticide (DZN-oxon) can be detected with our sensor.     

Use of Remote Sensing to Detect Soybean Cyst Nematode-Induced Plant Stress

Integrating remote sensing and geographic information systems (GIS) technologies offers tremendous opportunities for farmers to more cost effectively manage the causes of crop stress. Initial soybean cyst nematode (SCN) population densities from 995 2-×-3-m quadrats were obtained from a soybean field near Ames, Iowa, in 2000. The percentage of sunlight reflected from each quadrat was measured weekly using a multispectral radiometer beginning in mid-May and continuing through mid-September. Aerial images were obtained at heights above the field ranging from 45 to 425 m on 12 dates during the soybean growing season. This was accomplished using color film and infrared film in conjunction with a filter to measure reflectance in the near-infrared region (810 nm). Satellite images (Landsat 7) were obtained for five dates during the 2000 growing season. Maps depicting initial SCN population densities, soybean yield, soy oil, and soy protein were generated using the GIS software program ArcView. Percentage reflectance (810 nm), aerial image intensity, and satellite image intensity data then were regressed against soybean yield, soy oil, and soy protein concentrations obtained from each geospatially referenced soybean quadrat. Percentage reflectance measurements explained up to 60% of the variation in initial SCN population densities within soybean quadrats and up to 91% of the variation in soybean yield. Aerial image and satellite image intensities explained up to 80% and 47% of the variation in soybean yield, respectively. Percentage reflectance data also explained 36% and 54% of the variation in oil and protein concentrations of the harvested soybeans, respectively. These results indicate that remote sensing coupled with GIS technologies may provide new tools to detect and quantify SCN population densities and their impacts on the quantity and quality of soybean yield.     

Genetic mutation analysis at early stages of cell line development using next generation sequencing

A central goal for most biopharmaceutical companies is to reduce the development timeline to reach clinical proof of concept. This objective requires the development of tools that ensure the quality of biotherapeutic material destined for the clinic. Recent advances in high throughput protein analytics provide confidence in our ability to assess productivity and product quality attributes at early stages of cell line development. However, one quality attribute has, until recently, been absent from the standard battery of analytical tests facilitating informed choices early in cell line selection: genetic sequence confirmation. Techniques historically used for mutation analysis, such as detailed mass spectrometry, have limitations on the sample number and turnaround times making it less attractive at early stages. Thus, we explored the utility of Next‐Generation Sequencing (NGS) as a solution to address these limitations. Amplicon sequencing is one such NGS technique that is robust, rapid, sensitive, and amenable to multiplexing, all of which are essential attributes for our purposes. Here we report a NGS method based upon amplicon sequencing that has been successfully incorporated into our cell line development workflow alongside other high‐throughput protein analytical assays. The NGS method has demonstrated its value by identifying at least one Chinese hamster ovary (CHO) clone expressing a variant form of the biotherapeutic in each of the four clinical programs in which it has been utilized. We believe this sequence confirmation method is essential to safely accelerating the time to clinical proof of concept of biotherapeutics, and guard against delays related to sequence mutations. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:813–817, 2016     

基于3S技术的珠江三角洲景观格局动态变化述评

珠三角是一个景观格局与过程变化极为复杂的区域,近30年来,高速的经济增长与快速的城市化过程使珠三角的景观发生了剧烈的变化,随着全世界对生态环境发展的重视,该区域的景观变化研究也引起了众多专家和学者的关注。另外,随着遥感(RS)、地理信息系统(GIS)和全球定位系统(GPS)技术的发展和成熟,基于3S技术联合来监测和研究景观格局及其变化也成为研究的主流。因此,基于3S技术对珠江三角洲景观格局动态变化进行了大量的研究,并取得了一些成果。本文首先总结了基于3S技术监测景观格局动态变化;其次分析了这些方法在珠江三角洲地区中的应用;并提出几点展望,旨在为珠三角今后的景观格局变化监测研究提供一些必要的借鉴和支持。     

一种新型H5N1禽流感病毒血凝素抗原快速检测试剂的建立

利用5株广谱特异性抗H5亚型血凝素单克隆抗体和酶联免疫渗滤技术成功地建立了一种适于现场检测H5亚型禽流感病毒血凝素蛋白的抗原快速检测试剂H5-HA(Ag)Dot-ELISA。该试剂对41株代表当前亚洲地区流行的各种遗传变异亚系H5N1禽流感病毒检测均为阳性,对多数毒株的分析灵敏度优于0.1个血凝滴度(HA titer),其中部分优于0.01个血凝滴度;比较该试剂与早期开发的同类ELISA试剂,发现前者对后者未能检出的H5N1新变异株检测均为阳性;利用该试剂和商品化Directigen Flu A(BD)试剂检测两株H5N1病毒株,提示前者灵敏度高于后者;该试剂对一株H5N1病毒的检测灵敏度与标准RT-PCR相当;该试剂对24株非H5亚型病毒检测均为阴性,显示出良好特异性。以上结果提示,此研究建立的H5N1病毒抗原快速检测试剂在H5禽流感现场检测上具有较好的应用前景。