激光拉曼光谱无损分析浙贝母

通过采集浙江省5个浙贝母主产区不同生产基地的新鲜样品,获取浙贝母激光拉曼光谱的图谱,并进行特征峰分析和一阶导数分析。结果表明,浙贝母在875、912、965、1 153、1 312、1 410、1 482、1 598、1 641 cm^-1等位移处出现9处明显的特征峰,并初步判定了这些特征峰的归属。研究结果表明,采用拉曼光谱进行农产品分析具有无损、快速、简便的特点,研究结果获取的9个特征峰可以作为鉴别浙贝母真伪、产地、溯源的手段。     

Raman spectroscopic evidence for two conformations of uncomplexed valinomycin in the solid state

Raman spectroscopy is applied for the first time to elucidate the different conformations of the carrier transport molecule, valinomycin. Splitting of the ester and amide carbonyl stretch vibrations is observed in the Raman spectrum of crystals of valinomycin grown from both n-octane and acetone. These observations support the contention that some ester carbonyl groups are intramolecularly hydrogen bonded. The Raman spectrum of valinomycin grown from o-dichlorobenzene does not display this feature.     

基于SSR标记的福建省若干水稻品种DNA指纹图谱构建及遗传多样性分析

以24份杂交稻品种和18份杂交稻亲本为材料,利用SSR分子标记进行DNA指纹图谱构建和遗传多样性分析。24对引物在研究材料中共检测到74个多态性片段,平均每对引物的多态性片段为3.1个。基于24个SSR标记的扩增结果,利用NTSYS 2.10e软件计算Dice遗传相似系数,并建立UPGMA聚类图,结果表明:42份材料之间的相似系数变化范围为0.60~1.00,在遗传相似系数0.68处可以将42份材料分为6个类群,较好地反映了供试材料的亲缘关系,可为水稻育种中亲本选择提供参考。同时建立了42份材料×12个SSR标记的指纹图谱,为杂交水稻品种纯度和真伪鉴定提供科学数据。     

四川稻瘟病菌分子指纹聚类分析及与病菌致病型比较研究

应用rep-PCR(repetitive element-based pcdymerase chain reaction)分子指纹技术，对75个四川稻瘟病菌菌株进行了DNA分子指纹扩增和聚类分析。结果表明．供试菌株基因组用Pot 2-1和Pot 2-2引物共扩增出29条DNA谱带，其中14条为多态性DNA带，各菌株分别扩增出4到17条不等的带谱；经聚类分析，在0．19连锁距离点，所有供试菌株分为7个遗传宗亲群组，其中第5宗亲群和7宗亲群分别为优势宗亲群。供试菌株传统小种划分的致病型与遗传宗亲群之间没有明显的相关性。     

Scanometric DNA array detection with nanoparticle probes

A method for analyzing combinatorial DNA arrays using oligonucleotide-modified gold nanoparticle probes and a conventional flatbed scanner is described here. Labeling oligonucleotide targets with nanoparticle rather than fluorophore probes substantially alters the melting profiles of the targets from an array substrate. This difference permits the discrimination of an oligonucleotide sequence from targets with single nucleotide mismatches with a selectivity that is over three times that observed for fluorophore-labeled targets. In addition, when coupled with a signal amplification method based on nanoparticle-promoted reduction of silver(I), the sensitivity of this scanometric array detection system exceeds that of the analogous fluorophore system by two orders of magnitude.     

Water and solutions at negative pressure: Raman spectroscopic study to -80 megapascals

Microscopic inclusions of aqueous fluids trapped in interstices in quartz and other crystals provide novel systems for the deliberate study of liquids under tension. Liquids under tension should differ in interesting ways from those at ambient pressure or compressed liquids because attractive, rather than repulsive, forces should dominate their behavior. Static tensions in excess of 100 megapascals (~1000 atmospheres) have been obtained reproducibly. Video-recorded observations of the final liquid rupture process, coupled with extrapolations of data at positive pressure, suggest that the homogeneous vapor nucleation point was reached in two of the cases studied. Raman spectra of the fluids at -80 megapascals show that an isothermal volume stretch of -5 percent by volume has only a weak effect on the spectral features and is similar to the effect of isobaric heating.     

Array-based electrical detection of DNA with nanoparticle probes

A DNA array detection method is reported in which the binding of oligonucleotides functionalized with gold nanoparticles leads to conductivity changes associated with target-probe binding events. The binding events localize gold nanoparticles in an electrode gap; silver deposition facilitated by these nanoparticles bridges the gap and leads to readily measurable conductivity changes. An unusual salt concentration-dependent hybridization behavior associated with these nanoparticle probes was exploited to achieve selectivity without a thermal-stringency wash. Using this method, we have detected target DNA at concentrations as low as 500 femtomolar with a point mutation selectivity factor of approximately 100,000:1.     

DNA和RNA在细胞中的分布情况观察

利用经典的甲基绿-吡罗红染色方法显示细胞中的DNA与RNA,实验结果与理论有较大的偏差,为了以更简易的实验操作得到更清晰的结果,本研究对该实验进行了改进,即从是否需要盐酸解离、酸解时间、酸解温度、染色时间等方面进行改进。结果表明:上皮细胞不经酸解直接染色,实验结果明显;洋葱下表皮经过20℃质量分数为8%的盐酸解离2min后,染色2min效果明显;采用新材料白洋葱的上表皮直接染色4-5min效果明显。说明改进后的染色方法时间缩短,步骤简化,效果明显,可为生物学实验课教学提供参考。     

橡胶树炭疽菌孢子的拉曼光谱特征及其在聚类分析中的应用

为了弥补分类学上单纯依靠形态学与分子生物学鉴定炭疽菌的不足,基于共聚焦显微拉曼技术的橡胶树炭疽菌3个种群孢子聚类分析方法,对橡胶树炭疽菌孢子的拉曼光谱进行扫描,找到了其共有的位于1 005 cm?1, 1 155 cm?1和1 515 cm?1处的3个主要的拉曼峰以及其他次级峰,并对峰的产生来源进行初步确认。结合拉曼光谱与主成分分析（PCA）,依靠3个主要的拉曼峰以及其他次级峰在PC1、PC2以及PC3的三维空间得分图中快速有效地将3种橡胶树炭疽菌孢子区分开来,为鉴别炭疽菌孢子提供了一种新方法,满足了灵敏与微量的要求,且样品无需预富集和预处理。     

农田水样中微囊藻毒素-LR拉曼检测方法的研究

本研究建立了基于表面增强拉曼散射技术(Surface-enhanced Raman scattering,SERS)的农田水样中微囊藻毒素-LR(Microcystin-LR,MC-LR)的检测方法。采用柠檬酸钠还原法制备金种(Au nanoparticles,Au NPs),通过媒介增长法制备了刺状金纳米颗粒(Spiny gold nanoparticles,SGNPs),使用紫外-可见吸收光谱(Ultraviolet visible,UV-vis)、透射电镜(Transmission electron microscopy,TEM)和探针分子(对巯基苯甲酸,4-mercaptobenzoic acid,4-MBA)对SGNPs进行了表征及鉴定。研究以三角状金纳米颗粒作为基底,选择MC-LR在1 007 cm~(-1)和1 309 cm~(-1)处的特征峰作为定量峰,激光器激发波长为785 nm,积分时间20 s,建立检测方法。本研究建立的检测方法在1.0～100 000μg·L~(-1)的浓度范围内具有良好的线性关系,检测限(LOD)和回收率分别为1.0μg·L~(-1)和80%～102%,使用本方法对镇江市内运粮河及古运河的灌溉水样进行检测,MC-LR的检出率为40%,含量最高达1.81μg·L~(-1),检测结果与LC-MS/MS比对,相关系数为0.84。本研究建立的方法快速准确,前处理简单,能满足农田水样中MC-LR的现场快速检测的要求。     

Isopycnic centrifugation for the isolation of DNA strands coding for ribosomal RNA

Denatured DNA preparations from Escherichia coli were centrifuged to equilibrium in cesium chloride solutions. Hybridizing experiments with radioactively labeled ribosomal RNA showed that the DNA strands complementary to ribosomal RNA were distributed on the heavy side of the DNA band. By fractionating this band the DNA strands coding for ribosomal RNA may be enriched 5- to 20- fold.     

利用CTAB法从刺梨中提取核酸的效果分析

高质量DNA和RNA的获得是进行分子标记、基因克隆、分子杂交等分子生物学实验的基础.从植物组织中提取核酸的方法较多,针对不同植物主要有SDS法、CTAB法、异硫氰酸胍法等[1].刺梨作为原产于我国的一种新兴果树,近年来对其种质遗传多样性及特殊、珍稀性状的分子生物学研究逐渐受到重视.     

蒙古羊、兰州大尾羊和哈萨克羊随机扩增多态DNA分析

从 2 4个随机引物中筛选出 5个引物 ,对蒙古羊、兰州大尾羊和哈萨克羊 3个绵羊品种共计 89个个体进行了随机扩增多态 DNA分析 ,根据扩增片段计算了蒙古羊、兰州大尾羊和哈萨克羊扩增 DNA指纹条带的平均带纹数分别为 5 .32 ,5 .2 8和 5 .78;平均带纹相似率分别为 0 .5 9,0 .6 0和 0 .6 2 ;平均杂合度分别为 0 .75 ,0 .78和 0 .77。用 Nei氏片段共享度公式计算了 3个群体的遗传距离 ,构建了其关系图 ,聚类分析结果表明 ,蒙古羊与兰州大尾羊的遗传距离最小 (0 .0 34) ,彼此亲缘关系较近。相对而言 ,兰州大尾羊与哈萨克羊的遗传距离最大(0 .10 4 ) ,彼此亲缘关系较远。     

9个果蔗品种(系)遗传多样性分析及DNA指纹图谱构建

【目的】对9个果蔗品种(系)进行遗传多样性分析并构建其DNA指纹图谱,为果蔗品种鉴定和分子育种等提供理论依据。【方法】利用21个SSR分子标记和毛细管电泳技术对来自4个省份的9个果蔗品种(系)进行遗传多样性分析,应用NTSYS-pc 2.11计算供试材料间遗传相似系数,并运用UPGMA法进行聚类分析,同时构建其DNA指纹图谱。【结果】21对SSR引物共扩增出204条带,多态性比例为75.99%,每对引物可扩增出4~31条带,平均为9.71条。其中,17对引物含有9个果蔗品种(系)的44个特征位点,仅有5对引物鉴别能力最强,单个引物即可将其完全区分开。选择多态性高、鉴别力强且含有品种(系)特征位点的3对引物(SMC36BUQ、SMC597CS和SMC851MS)构建了9份果蔗品种(系)基于44个位点的DNA指纹图谱。9份果蔗材料的遗传相似系数为0.62~0.90,平均为0.77。UPGMA聚类结果显示,9个果蔗材料可分为三大类群,且与材料来源地无直接关系。【结论】9个果蔗品种(系)间的遗传基础差异较小,亲缘关系较近,遗传多样性并不丰富,在育种中应加大果蔗亲本遗传背景的差异,提高其遗传多样性。     

"夏光"、"早夏16"甘蓝杂交种DNA指纹图谱的构建

用SDS法提取甘蓝(Brassica oleraceavar.capitata)杂交种“夏光”、“早夏16”及其各自亲本的基因组DNA,通过SSR、RAPD两种分子标记方法构建其DNA指纹图谱用于纯度鉴定。利用30对甘蓝SSR引物和50个适用于甘蓝的RAPD引物,以各杂交种及其亲本的基因组DNA为模板组合进行筛选,结果显示:多数SSR引物对两组合扩增带型一致,未能建立SSR指纹图谱;通过RAPD标记方法筛选出能鉴定两杂交种纯度的引物分别为S15、S42、S147和S42、S78、S88,其中引物S42对两组合均能扩增出特异的RAPD指纹图谱,并将RAPD指纹图谱转变为相应的数字指纹。