缠结聚合物溶液毛细管电泳

从缠结聚合物溶液理论及其电泳迁移理论对缠结聚合物溶液毛细管电泳的现状给予综述，并就缠结聚合物溶液毛细和电泳在ＤＮＡ，蛋白质等大分子分离方面的应用进行了概述。     

毛细管电泳中聚合物溶液筛分脱氧核糖核酸

围绕着毛细管电泳中聚合物溶液筛分脱氧核糖核酸（ＤＮＡ）的机理和分离介质、条件,综述了近年来该技术的发展,及其在ＤＮＡ测序、聚合酶链反应（ＰＣＲ）产物分析方面的应用及其发展前景。     

基于温敏性N,N-二甲基丙烯酰胺/N-异丙基丙烯酰胺无规共聚物的毛细管无胶电泳筛分介质北大核心CSCD

本文合成了N,N-二甲基丙烯酰胺/N-异丙基丙烯酰胺无规共聚物(P(DMA-co-NIPAM))和聚N,N-二甲基丙烯酰胺(PDMA),并将二者共混制备毛细管无胶电泳筛分介质,旨在降低筛分介质粘度的同时增强其对DNA的分离性能。核磁共振氢谱(1H NMR)和傅里叶变换红外光谱(FT-IR)证明了2种聚合物的成功合成。表征了P(DMA-co-NIPAM)/PDMA共混物溶液的流体力学直径(Dh)、低剪切粘度和吸光度,结果表明,P(DMAco-NIPAM)聚合物具有温敏性,低临界溶解温度(LCST)为60~80℃。DNA筛分结果显示,PDMA中添加了10%P(DMA-co-NIPAM)的复合筛分介质性能最好,相比PDMA粘度降低19%以上,对大DNA片段的分辨率和理论塔板数均明显提高,分离时间缩短4%,显示了优良的分离性能。     

用于毛细管电泳DNA分离的合成聚合物*

毛细管电泳的无胶筛分方法在DNA片段分离、DNA 测序方面取得了显著的成绩并已成功应用于人类基因组计划.该法是在毛细管柱中充入一定浓度和组成的线性高分子溶液,利用其对样品组分电泳迁移时的阻滞作用,按分子量大小对DNA等生物大分子进行筛分分离分析.因此,聚合物筛分介质的类型、组成和性质会显著影响分离效果.近年来,由于受到基因组计划的影响,出现了许多用于DNA片段分离和DNA测序的水溶性高分子聚合物,并取得很大进展.本文按照均聚物和共聚物的分类,综述了作为筛分介质的各种合成聚合物及其应用效果,并简要介绍了有关的筛分理论和分离的评价指标.     

毛细管无胶筛分电泳中一种DNA定量分离模型的优化讨论

对已建立的交缠聚合物溶液中DNA定量分离模型的影响因素,如DNA尺寸、电场强度、聚合物性质及聚合物质量浓度等进行了讨论,并就该模型对聚合物介质选择的指导性进行评价.实验证明,DNA链越长,电泳迁移的时间越长;聚合物相对分子质量越高,越利于长链DNA的分离;筛分聚合物质量浓度越高,DNA分离时所需的迁移时间越长;快速分离要求使用较大的场强,而基于对大片段DNA的有效分离则应限制高场强的使用.该模型还可用于计算DNA分离的最佳聚合物质量浓度,结果表明高质量浓度聚合物有利于DNA的筛分.以上实验结果和模型预测的结论一致,对DNA电泳分离模型的研究有较大的促进作用,对毛细管无胶筛分电泳实验参数的选择和优化具有一定的指导意义.     

动力学涂层毛细管电泳分离双链脱氧核糖核酸片段

以异丙醇为聚合反应链转移试剂，水相法合成了短链聚N，N－二甲基丙烯酰胺（PDMA），研究表明，该聚合物能在毛细管内壁形成稳定的动力学涂层，从而有效地抑制电渗流和毛细管内壁与DNA的作用。这种介质被成功地应用于DNA片段的高效分离。     

毛细管电泳检测神经细胞凋亡

建立了毛细管电泳检测凋亡细胞DNA片段的方法.以DNA相对分子质量标准品为溶质,考察了分离条件(电压、进样时间、温度、聚合物浓度)对分离的影响.在优化条件下,利用毛细管无胶筛分电泳对缺氧缺血过程中不同时间点神经PC12细胞DNA片段进行了分析,并与流式细胞仪结果比较,研究缺氧缺血时胶质细胞凋亡过程.     

分子烙印聚合物作为高效毛细管电泳添加剂的研究

分子洛印聚合物（molecular imprinted polymer)是一种高选择的有分子记忆效应的主体分子,通常在非极性环境中制备和应用。该文在极性溶剂中利用离子化作用和疏水作用制备了非共价的分子烙印聚合物,并将其作为高效毛细管电泳流动相添加剂;在含水缓冲溶液条件下,研究了单体种类、分子烙印聚合物颗粒度和含量、缓冲溶液pH值以及分离电压对分子烙印聚合物识别模板分子的影响。结果证明了在质子溶剂中制备和应用非共价分子烙印聚合物是可行的。     

用未涂敷毛细管电泳分离DNA片段

用内壁未涂敷毛细管，以羟乙基纤维素的无胶筛分介质，在６ｍｉｎ内分离了λＤＮＡ／ＥｃｏＲＩ＋ＨｉｎｄⅢ片段，探讨了ＤＮＡ片段在未涂敷毛细管中的分离机理，讨论了羟乙基纤维素和缓冲溶液浓度及电压对分离的影响，考察了ＤＮＡ片段迁移时间的重现性。     

人的基因组及DNA序列分析：过去,现在及将来（下）

对ＤＮＡ序列分析方法如毛细管电泳、阵列毛细管电泳、超薄层板电泳作了详细评述。并对正在研究开发不用电泳分离的直接测序新技术和新方法，如质谱法、原子探针法（扫描隧道显微镜、原子力显微镜）、杂交法、流动式单分子荧光检测法等进行了评论。     

Length-dependent DNA separations using multiple end-attached peptide nucleic acid amphiphiles in micellar electrokinetic chromatography

End-labeled free-solution electrophoresis (ELFSE) is an alternative approach to gel-based methods for size-based electrophoretic separation of DNA. In ELFSE, an electrically neutral "drag-tag" is appended to DNA to add significant hydrodynamic drag, thereby breaking its constant charge-to-friction ratio. Current drag-tag architecture relies on covalent attachment of polymers to each DNA molecule. We have recently proposed the use of micellar drag-tags in conjunction with sequence-specific hybridization of peptide nucleic acid amphiphiles (PNAAs). This work investigates the effect of multiple PNAA attachment on DNA resolution using MEKC. Simultaneous PNAA hybridization allows for the separation of long DNA targets, up to 1012 bases, using micellar drag-tags. Each PNAA handle independently interacts with the micellar phase, reducing the overall mobility of this complex relative to individual PNAA binding. The sequence- and size-based dependence of this separation technique is maintained with multiple PNAA binding over a range of DNA sizes. Results are accurately described by ELFSE theory, yielding alpha=54 for single-micelle tagging and alpha=142 for dual-micelle tagging. This method is the first example of a non-covalent drag-tag used to separate DNA of 1000 bases based on both size and sequence.     

Star-shaped polymers for DNA sequencing by capillary electrophoresis

The separation and sequencing of DNA are the main objectives of the Human Genome Project, and this project has also been very useful for gene analysis and disease diagnosis. Capillary electrophoresis (CE) is one of the most common techniques for the separation and analysis of DNA. DNA separations are usually achieved using capillary gel electrophoresis (CGE) mode, in which polymer gel is packed into the capillary. Compared with a traditional CGE matrix, a hydrophilic polymer matrix, which can be adsorb by the capillary wall has numerous advantages, including stability, reproducibility and ease of automation. Various water-soluble additives, such as linear poly(acrylamide) (PAA) and poly(N,N-dimethylacrylamide) (PDMA), have been employed as media. In this study, different star-shaped PDMA polymers were designed and synthesized to achieve lower polymer solution viscosity. DNA separations with these polymers avoid the disadvantages of high viscosity and long separation time while maintaining high resolution (10 bp between 271 bp and 281 bp). The influences of the polymer concentration and structure on DNA separation were also determined in this study; higher polymer concentration yielded better separation performance, and star-like polymers were superior to linear polymers. This work indicates that modification of the polymer structure is a potential strategy for optimizing DNA separation.     

A viscosity-tunable polymer for DNA separation by microchip electrophoresis

A thermo-responsive separation matrix, consisting of Pluronic F127 tri-block copolymers of poly(ethylene oxide) and poly(propylene oxide), was used to separate DNA fragments by microchip electrophoresis. At low temperature, the polymer matrix was low in viscosity and allowed rapid loading into a microchannel under low pressure. With increasing temperatures above 25°C, the Pluronic F127 solution forms a liquid crystalline phase consisting of spherical micelles with diameters of 17–19 nm. The solution can be used to separate DNA fragments from 100 bp to 1500 bp on poly(methyl methacrylate) (PMMA) chips. This temperature-sensitive and viscosity-tunable polymer provided excellent resolution over a wide range of DNA sizes. Separation is based on a different mechanism compared with conventional matrices such as methylcellulose. To illustrate the separation mechanism of DNA in a Pluronic F127 solution, DNA molecular imaging was performed by fluorescence microscopy with F127 polymer as the separation matrix in microchip electrophoresis. Figure Temperature dependence of the viscosity of 20% w/w Pluronic F127 solution in 1xTBE buffer. Dotted approximates resultant curve.     

Nonaqueous and aqueous capillary electrophoresis of synthetic polymers

In this work, the use of capillary electrophoresis (CE) to analyze synthetic polymers is reviewed including works published till February 2004. The revised works have been classified depending on the CE mode (e.g., free solution capillary electrophoresis, capillary gel electrophoresis, etc.) and type of buffer (i.e., nonaqueous, aqueous and hydro-organic background electrolytes) employed to separate synthetic macromolecules. Advantages and drawbacks of these different separation procedures for polymer analysis are discussed. Also, physicochemical studies of complex polymer systems by CE are reviewed, including drug release studies, synthetic polyampholytes, dendrimers, fullerenes, carbon nanotubes and associative copolymers.     

Low viscosity DNA sieving matrices for capillary electrophoresis

The rapid development of DNA capillary electrophoresis (CE) technology has increased the demand of new low viscosity sieving matrices with high separation capacity. The high throughput, resolution and automatic operation of CE systems have stimulated the application of the technique to different kinds of DNA analysis, including DNA sequencing, separation of restriction fragments, PCR products and synthetic oligonucleotides. In addition specific methods for PCR-based mutation assays for the study of known and unknown point mutations have been developed for use in CE. The key component for a large scale application of CE to DNA analysis is the availability of appropriate sieving matrices. This article gives an overview of the linear polymers used as DNA separation matrices with particular emphasis on the polymers that combine high sieving capacity, low viscosity and chemical resistance.     

Manipulation of Polymer Chain Entanglement and Self-Assembly for DNA Capillary Electrophoresis

A conceptual model has been developed and tested experimentally on five different aspects, relating to the architecture and topology of the polymers making up the transient network that constitutes the separation matrix. The concept can be applied for DNA sequencing analysis and separations of short fragments double-stranded DNA as well as oligonucleotides. Examples are provided to illustrate the success of the concept.     

聚苯乙烯大单体与丙烯酸丁酯接枝共聚物的微观分相与表面性能研究

研究了以大单体技术合成的不同侧链长度的苯乙烯与丙烯酸丁酯的接枝共聚物的侧链长度对其微观分相与表面性能的影响,发现仅当聚苯乙烯侧链分子量大于5900时,才可能发生部分微观相分离,分离后对其表面性能影响不明显。临界表面张力r_c虽有差异,但色散力部分y_s^D的计算值却较一致,与所用参照液无关。实验证实,接枝共聚物的表面几乎全被低表面能的聚丙烯酸丁酯骨架所复盖,呈现出明显的表面富集现象。     

Water-Soluble Copolymers. XX. Copolymers of Acrylamide with Sodium 3-(N-Propyl)Acrylamido-3-Methylbutanoate: Solution Properties

Dilute solution properties of copolymers of acrylamide (AM) with sodium 3-(N-propyl)acrylamido-3-methylbutanoate (NaPAMB) of known molecular weight have been studied as a function of composition, temperature, time, pH, and added electrolytes. Phase separation and potentiometric studies have also been performed. The AM-NaPAMB copolymers possess lower molecular weights and solution viscosities than the AM-NaAMB copolymers. In addition, the AM-NaPAMB polymers exhibit moderate viscosity-temperature coefficients and poor salt tolerance. These polymers undergo phase separation in the presence of divalent cations as a function of temperature. The observed properties can be related to the steric and hydrophobic effects caused by the presence of the n-propyl substituent at the amide nitrogen.     

Separation of oligonucleotides and DNA fragments by capillary electrophoresis in dynamically and permanently coated capillaries,using a copolymer of acrylamide and β-D-glucopyranoside as a new low viscosity matrix with high sieving capacity

New copolymers of acrylamide and β-D -glucopyranoside were synthesized and characterized. The different reactivity of the two monomers towards radical polymerization meant we could control the growth of the polymer chains whose length was inversely related to the number of glucose residues incorporated in the copolymers. The properties of these polymers were investigated in the separation of oligonucleotides and double-stranded DNA by capillary electrophoresis (CE) in coated and uncoated capillaries. The new copolymers were a suitable matrix for CE due to their high-resolving capacity and low viscosity. We also looked into the advantages of a new method of dynamic suppression of electroosmotic flow based on the addition of small amounts (0.03–0.05%) of dimethylacrylamide to the sieving and to the running buffer. A complete test was run on the reproducibility and efficiency of separations carried out in a permanently and dynamically coated capillary, and the advantages and disadvantages of the two methods were compared.