共查询到20条相似文献，搜索用时 562 毫秒
1.
Syed Mazher Husain M. P. J. S. Anandaraj 《Indian journal of clinical biochemistry : IJCB》1997,12(2):142-145
DNA samples from a family (parents and a son) with hereditary persistence of fetal hemoglobin (HPFH) condition were subjected to amplification of a 1.214 kbp DNA fragment from β-globin gene using polymerase chain reaction (PCR). The aim of this study was to identify the type of HPFH i.e. deletional or non deletional. Non deletional type of HPFH was identified in two samples and moreover, these samples were found to be associated with 619bp β°-thalassemia deletion. This is the first report on the association of non deletional HPFH with 619bp β°-thalassemia deletion. 相似文献
2.
We have used Brownian dynamics-finite element method (BD-FEM) to guide the optimization of a microfluidic device designed to stretch DNA for gene mapping. The original design was proposed in our previous study [C. C. Hsieh and T. H. Lin, Biomicrofluidics 5(4), 044106 (2011)] for demonstrating a new pre-conditioning strategy to facilitate DNA stretching through a microcontraction using electrophoresis. In this study, we examine the efficiency of the original device for stretching DNA with different sizes ranging from 48.5 kbp (λ-DNA) to 166 kbp (T4-DNA). The efficiency of the device is found to deteriorate with increasing DNA molecular weight. The cause of the efficiency loss is determined by BD-FEM, and a modified design is proposed by drawing an analogy between an electric field and a potential flow. The modified device does not only regain the efficiency for stretching large DNA but also outperforms the original device for stretching small DNA. 相似文献
3.
Size-dependent trajectories of DNA macromolecules due to insulative dielectrophoresis in submicrometer-deep fluidic channels 总被引：1，自引：0，他引：1
Gea O. F. Parikesit Anton P. Markesteijn Oana M. Piciu Andre Bossche Jerry Westerweel Ian T. Young Yuval Garini 《Biomicrofluidics》2008,2(2)
In this paper, we demonstrate for the first time that insulative dielectrophoresis can induce size-dependent trajectories of DNA macromolecules. We experimentally use λ (48.5 kbp) and T4GT7 (165.6 kbp) DNA molecules flowing continuously around a sharp corner inside fluidic channels with a depth of 0.4 μm. Numerical simulation of the electrokinetic force distribution inside the channels is in qualitative agreement with our experimentally observed trajectories. We discuss a possible physical mechanism for the DNA polarization and dielectrophoresis inside confining channels, based on the observed dielectrophoresis responses due to different DNA sizes and various electric fields applied between the inlet and the outlet. The proposed physical mechanism indicates that further extensive investigations, both theoretically and experimentally, would be very useful to better elucidate the forces involved at DNA dielectrophoresis. When applied for size-based sorting of DNA molecules, our sorting method offers two major advantages compared to earlier attempts with insulative dielectrophoresis: Its continuous operation allows for high-throughput analysis, and it only requires electric field strengths as low as ∼10 V∕cm. 相似文献
4.
Recent simulations by Chen and Dorfman [Electrophoresis 35, 405–411 (2014)]
suggested that “tilting” the electric field with respect to the lattice vectors of a hexagonal post
array would lead to a substantial improvement in electrophoretic DNA separations therein. We
constructed such an array where the electric field is applied at an angle equidistant between the
two lattice vectors. This tilted array leads to (i) baseline resolution of 20 kbp DNA and λ DNA
(48.5 kbp) in a 4 mm channel and (ii) measurable separation resolutions for electric fields up to
50 V/cm, both of which are improvements over untilted post arrays of the same post density. The
predicted time required to reach a resolution of unity is approximately 5 min, independent of
electric field. The separations are more reproducible at higher fields. 相似文献
5.
We report the profiling of the 5-methyl cytosine distribution within single genomic-sized DNA molecules at a gene-relevant resolution. This method linearizes and stretches DNA molecules by confinement to channels with a dimension of about 250×200 nm(2). The methylation state is detected using fluorescently labeled methyl-CpG binding domain proteins (MBD), with high signal contrast and low background. DNA barcodes consisting of methylated and non-methylated segments are generated, with both short and long concatemers demonstrating spatially resolved MBD binding. The resolution of the technique is better than 10 kbp, and single-molecule read-lengths exceeding 140 kbp have been achieved. 相似文献
6.
A featured microchip owning three big reservoirs and long turned geometry channel was designed to improve the detection limit of DNA fragments by using floating electrokinetic supercharging (FEKS) method. The novel design matches the FEKS preconcentration needs of a large sample volume introduction with electrokinetic injection (EKI), as well as long duration of isotachophoresis (ITP) process to enrich low concentration sample. In the curved channel [∼45.6 mm long between port 1 (P1) and the intersection point of two channels], EKI and ITP were performed while the side port 3 (P3) was electrically floated. The turn-induced band broadening with or without ITP process was investigated by a computer simulation (using CFD-ACE+ software) when the analytes traveling through the U-shaped geometry. It was found that the channel curvature determined the extent of band broadening, however, which could be effectively eliminated by the way of ITP. After the ITP-stacked zones passed the intersection point from P1, they were rapidly destacked for separation and detection from ITP to zone electrophoresis by using leading ions from P3. The FEKS carried on the novel chip successfully contributed to higher sensitivities of DNA fragments in comparison with our previous results realized on either a single channel or a cross microchip. The analysis of low concentration 50 bp DNA step ladders (0.23 μg∕ml after 1500-fold diluted) was achieved with normal UV detection at 260 nm. The obtained limit of detections (LODs) were on average 100 times better than using conventional pinched injection, down to several ng∕ml for individual DNA fragment. 相似文献
7.
Syed Mazher Husain M. P. J. S. Anandaraj 《Indian journal of clinical biochemistry : IJCB》1995,10(2):122-125
Hemoglobin E (beta-26Glutamic acid→Lysine) is the second most prevalent hemoglobin variant in the world. 293 blood samples from cases referred from several hospitals in the region of Andhra Pradesh were screened for the detection of hemoglobinopathies. Four samples were found to be in heterozygous state for Hb E condition. Mutation in two of these heterozygotes was analysed using a 722 base pair (bp) amplified DNA fragment from beta-globin gene and restriction enzyme Mnl 1. A 232bp DNA fragment was found to be associated with the Hb E mutation. 相似文献
8.
拟南芥GH3基因家族启动子序列分析 总被引：1，自引：0，他引：1
GH3 基因家族是植物生长素早期响应基因家族之一.拟南芥 10个GH3 基因启动子序列分析表明:GH3 基因的转录起始位点一般在起始密码子上游65~145bp之内,TATA box大多分布在(-24)~(-40)bp区域.MDB和MatInspector分析显示,AtGH3 s基因的上游调控区域普遍存在组织和器官特异性表达元件、激素响应元件以及环境响应元件,表明GH3 基因的表达受到多因素调控;同时,基因芯片数据显示AuxREs对生长素的响应非常重要,但也可能存在其他的生长素响应元件. 相似文献
9.
本文测定了苦苣苔亚科4族、5属、5种植物的核糖体DNA中的内转录间隔区(ITS)序列及5．8s
rRNA基因的3′端序列。这几种苦苣苔亚科植物的ITS-1的长度范围为234～258 bp,ITS-2的长度范
围为218～246bp。Whytockia bijieensis的ITS-1(258bP)和ITS-2(218 bp)在长度、序列及GC含量上
均与其它几个种有较大差异,其代表的尖舌苣苔族可能很早就自苦苣苔亚科的祖先沿单独的一个分支
演化。以w．bijieensis作为功能性外类群,运用PAUP软件分析仅得到一个最简约树。在简约树上,
Cyrtandra umbelliferm、Briggsia longipes和Anna mollifolia形成一个单系群,bootstrap分析对该分支的
支持强度达97％,Chirita crasslfolia位于该分支的基部。由于系统树上Cyrtandra umbellifera代表的
浆果苣苔族和Anna mollifolid代表的芒毛苣苔族均起源于长蒴苣苔族,结合这3个族在形态上存在过渡系列,建议将浆果苣苔族和芒毛苣苔族均并入长蒴苣苔族。 相似文献
10.
We present an application of a novel DNA separation matrix, cholesterol-bearing pullulan (CHP) nanogels, for microchip electrophoresis. The solution of the CHP showed a unique phase transition around 30 mg∕ml and formed gel phase over this critical concentration. This gel phase consists of the weak hydrophobic interactions between the cholesterols could be easily deformed by external forces, and thus, loading process of the CHP nanogels into microchannels became easier. The high concentration of the CHP nanogels provided excellent resolutions especially for small DNA fragments from 100 to 1500 bp. The separation mechanism was discussed based on Ogston and Reptation models which had developed in gels or polymer solutions. The result of a single molecule imaging gave us an insight of the separation mechanism and the nanogel structures as well. 相似文献
11.
对Beesia calthifolia等5种金莲花亚科植物的核糖体DNA中的内转录间隔区(ITS)序列及5．8S
rRNA基因的3′端序列进行了测定。这几种金莲花亚科植物的ITS-1的长度范围为225～232 bp,ITS-2
的长度范围为201～217 bp。B．calthifolia的ITS-1(227 bp)和ITS-2(215 bp)的长度及序列均与升麻
属及类叶升麻属植物相近,其5.8S rRNA基因的3′端序列也近乎与升麻属及类叶升麻属植物完全一致
(仅一个碱基缺失的差异),但其在上述几方面均与金莲花属植物相差甚远。以Ranunculus enysii作为
外类群,运用PAUP软件进行的系统发育分析表明:B．calthifolia,Cimicifuga acerina,C．brachycarpa
和Actaea asiatica形成一个单系群,并得到bootstrap分析的极强支持,B．calthifolia位于这一单系群的
基部。这一DNA序列分析结果与来自植物化学、孢粉学和细胞学的研究结果相吻合,更进一步支持铁破锣属是升麻族的自然成员,并可能是升麻族中一个最原始的类群。 相似文献
12.
研究了国产防己科蝙蝠葛族tirb．Menispermeae9属20种和外类群青牛胆族trib．Tinosporeae 2属3种植物完整的ITS(包括5.8S rDNA)序列。trib．Menispermeae的ITS长527～601 bp，排序后长667bp。当gap处理为missing时具281个有信息位点。PAUP软件分析结果表明：①trib．Menispermeae是一个单系类群，该分支得到hootstrap l00％的支持；②确定了存疑种Pachygone valida的系统学位置，该种是Coc—culus属的成员；③Sinomenium和Menispermum两属有很近的系统学关系，组成族内稳定的一支，它们的ITS序列同源性极高，ITS1比族内其它属长41～73bp；④Stephania和Cyclea也是系统发育关系很近的两个类群。前者具两个主要分支，其IIS1、ITS2的G+C含量差异较大，在种类组成上，该两大支与传统上Stephania属内处理的2个亚属——千金藤亚属subgen．Stephania和山乌龟亚属subgen．Tuberiphania基本一致；Cyclea属内种间的ITS序列差异小，同源性极高。 相似文献
13.
对广义百合科黄精族6属23种及铃兰族1属1种的叶绿体基因组trnK和rpl16两个基因片段进
行了PCR-RFLP分析,结果表明：trnK基因的PCR产物在各类群间几乎不存在长度变异,均约2600bp,而rpl16基因则在各属之间及黄精属内表现出长度变异,变异范围在1140~1320bp之间;限制性酶切位点的同源性分析显示,黄精属、竹根七属、鹿药属和舞鹤草属构成的狭义黄精族与铃兰族中的铃兰属有较近的亲缘关系,并支持将扭柄花属和万寿竹属从广义百合科黄精族中分出的观点;在狭义黄精族内,黄精属与竹根七属聚成一支,鹿药属与舞鹤草属聚成另一支,为探讨族内属间的系统演化关系提供了分子生物学方面的证据。另外,本研究结果支持将金佛山黄精从鹿药属转隶至黄精属的观点。 相似文献
14.
Frequency-dependent behaviors of individual microscopic particles in an optically induced dielectrophoresis device 总被引：1，自引：0，他引：1
An optoelectronic microdevice is set up to drive single microparticles and a maximum synchronous velocity (MS-velocity) spectrum method is proposed for quantifying the frequency-dependent behaviors of individual neutral microparticles from 40 kHz to 10 MHz. Dielectrophoretic behaviors of three types of microparticles are investigated under the optically induced nonuniform electric field. Different MS-velocity spectra for the three different particles are experimentally found. Numerical calculations for the MS-velocity spectra of polystyrene microparticles are performed. The spectrum of the MS-velocities for a specific particle is mainly determined by the particle inherent property and the electric characteristics of the device. Moreover the experimental and the numerical MS-velocity spectra are compared to be accordant. Based on the dielectrophoretic (DEP) behaviors of the particles under a nonuniform electric field, microparticles can be finely characterized or distinguished according to their distinct MS-velocity spectra. 相似文献
15.
Angom Ranjana Devi Mahuya Sengupta Dipu Mani Barman Yashmin Choudhury 《Indian journal of clinical biochemistry : IJCB》2021,36(3):296
Nicotine, responsible for the addictive properties of tobacco, is widely used in nicotine replacement therapy for tobacco use cessation. We investigated the time-dependent effect of treatment with nicotine on the tumor suppressor, DNA repair and immune responses. Swiss Albino mice (laca strain) of both sexes received nicotine dissolved at a dose of 100 µg/ml in 2% sucrose for 24 weeks, by oral gavage, while age- and gender-matched controls received only 2% sucrose for the same period. Nicotine-treated and control mice were sacrificed 6, 16 and 24 weeks post-treatment, and their tissues evaluated for alterations in histology, oxidative stress, TNF-α levels, nitric oxide (NO) and myeloperoxidase (MPO) release, tumor suppressor response and DNA repair response. Statistical significance of results was determined using Students’ t test. The tissues of nicotine treated mice exhibited a large number of multinucleated and binucleated cells, enlarged nuclei and non-uniform distribution of cells, significant increase in expression of TNF-α gene and serum TNF-α, and time-dependent significant increase in lipid peroxidation, protein carbonylation, NO and MPO release when compared to age-and gender-matched controls. The mRNA expression of the tumor suppressor gene p53, its primary regulator Mdm2, and the DNA repair genes Brca2 and Ape1 were significantly elevated, but the corresponding protein levels remained largely unaltered. In conclusion, treatment with nicotine caused oxidative stress and inflammation which can cause widespread cellular damage from the very onset of treatment, without subverting the tumor suppressor and DNA repair responses.Electronic supplementary materialThe online version of this article (10.1007/s12291-020-00903-8) contains supplementary material, which is available to authorized users. 相似文献
16.
Three different sets of primers were designed using FASTA homology search and PRIMERSELECT for the specific detection ofNeisseria gonorrhoeae using polymerase chain reaction (PCR). These primers amplified the highly conserved regions of genes for Open Reading Frame
(ORF), Outer Membrane Protein (OMP) and 23S rRNA sequences ofN. gonorrhoeae. Each of the PCR primer set was evaluated using the DNA samples isolated from eight different positive isolates ofN. gonorrhoeae cultured from urethral swabs of patients visiting Maulana Azad Medical College and Safdarjung Hospital. Amplification products
were analyzed on agarose gel electrophoresis. Two sets of PCR primers, designated as Ngu1/Ngu2 and Ngu5/Ngu6, specific for
ORF and OMP gene respectively, amplified four regions of the gene which may help to differentiate the various strains ofN. gonorrhoeae infecting indigenous population. In contrast, a single, specific PCR product of 650 bp was visualized on agarose gel with
primers Ngu3/Ngu4, amplifying the 23S rRNA gene. Under optimum conditions, as low as 25ng of DNA isolated from eight different
clinical strains ofN. gonorrhoeae could be detected by PCR using Ngu3/Ngu4 set of primers. Our results suggested that Ngu3/Ngu4 could serve as good primers
for the specific, reproducible and sensitive diagnosis ofNeisseria gonorrhoeae from clinical samples. 相似文献
17.
Dielectrophoretic nanocolloid assay is a promising technique for sensitive molecular detection and identification, as target molecule hybridization onto the probe-functionalized nanocolloids can change their surface conductance and consequently their dielectrophoretic crossover frequencies. Thus, instead of relying on surface charge density increase after hybridization, as in many capacitive and field effect transistor impedance sensing techniques, the current assay utilizes the much larger surface conductance (and dielectrophoresis crossover frequency) changes to effect sensitive detection. Herein, we present a Poisson–Boltzmann theory for surfaces with finite-size molecular probes that include the surface probe conformation, their contribution to surface charge with a proper delineation of the slip and Stern planes. The theory shows that the most sensitive nanocolloid molecular sensor corresponds to a minimum in the dielectrophoretic crossover frequency with respect to the bulk concentration of the molecular probes (oligonucleotides in our case) during nanocolloid functionalization. This minimum yields the lowest number of functionalized probes that are also fully stretched because of surface probe-probe interaction. Our theory provides the surface-bulk oligonucleotide concentration isotherm and a folding number for the surface oligonucleotide conformation from the crossover frequency, the zeta potential, and the hydrodynamic radius data. 相似文献
18.
BackgroundThe salivary glands of Lucilia sericata are the first organs to express specific endopeptidase enzymes. These enzymes play a central role in wound healing, and they have potential to be used therapeutically.MethodsRapid amplification of cDNA ends and rapid amplification of genomic ends were used to identify the coding sequence of MMP-1 from L. sericata. Different segments of MMP1 gene, namely the middle part, 3′ end, and 5′ end, were cloned, sequenced, and analyzed using bioinformatics tools to determine the distinct features of MMP-1 protein.ResultsAssembling the different segments revealed that the complete mRNA sequence of MMP-1 is 1932 bp long. CDS is 1212 bp long and is responsible for the production of MMP-1 of 404 amino acid residues with a predicted molecular weight of 45.1 kDa. The middle part, 3′ end, and 5′ end sequences were 933, 503, and 496 bp. In addition, it was revealed that the MMP-1 genomic sequence includes three exons and two introns. Furthermore, the three-dimensional structure of L. sericata MMP-1 protein was evaluated, and its alignment defined that it has high similarity to chain A of human MMP-2 with 100% confidence, 72% coverage, and 38% identity according to the SWISS-MODEL modeling analysis.ConclusionsMMP-1 of L. sericata has a close relationship with its homologs in invertebrates and other insects. The present study significantly contributes to understanding the function, classification, and evolution of the characterized MMP-1 from L. sericata and provides basic required information for the development of an effective medical bioproduct. 相似文献
19.
20.
Orathai Tangvarasittichai Watchiravut Jaiwang Surapon Tangvarasittichai 《Indian journal of clinical biochemistry : IJCB》2015,30(1):55-58
Increased levels of plasma DNA have frequently been noticed in the blood plasma of cancer patients. The possibility of using plasma DNA level as the indicator of tumor stage in breast cancer was investigated in plasma samples obtained from 100 breast cancer patients and 100 healthy women who were included as controls. Circulatory plasma free DNA was extracted from plasma samples and quantified by fluorometer. The median concentration of plasma DNA in the plasma samples from breast cancer patients classified by TNM staging system as stage I, II, III, IV and breast surgical patients were 0.5, 235, 422, 1,280 and 0.5 ng/ml, respectively. The level of plasma DNA in the stage II- IV group was significantly higher than those in the surgical group with breast cancer and control group (P value < 0.001). The plasma DNA concentration in stage II, III and IV of breast cancer were higher when compared with healthy group. These tumor size, TNM stage and metastasis were significantly correlated with plasma DNA. The cut point of 120 ng/ml was early screening and treatment follow up breast cancer. 相似文献