中科大高分子课件（五）聚合物在生物高分子分离中的应用

1、,电渗是CE的基本现象之一，它可以控制组分的迁移速度和方向，进 而影响CE的分离效率和重现性,如何控制电渗流？,理论： 能影响电渗的因素都有可能用于电渗的控制 实际： 能理想地调节电渗而又不影响分离过程的控制方法目前 不多见 对于DNA分离及测序来说，pH-8.3，常用管壁涂层（涂覆) 技术.,化学涂覆,如聚丙烯酰胺、聚乙烯基吡咯烷酮涂层可在pH9-pH6以内基本消除电渗,优点,抑制熔硅毛细管表面SiOH解离，修饰表面Zeta电势 聚合物或硅烷化试剂的取代基覆盖已离解的SiOH 增加了内壁表面层附近溶液的粘度，涂层的厚度和密度都将影响到表面 层附近溶液的粘度，从而影响涂层的涂覆效果。 涂层寿命

2、长，稳定性好，分离效率高。,缺点,化学键合的过程中涉及毛细管硅烷化和引发单体聚合两步反应，一方面受两步反应的转化率影响，SiOH很难被完全屏蔽；另一方面，毛细管内的聚合反应很难控制，容易造成涂层的不均一性、不规整性，甚至阻塞毛细管。 价格昂贵。,物理涂覆,涂层制备过程简单易操作，涂覆过程可一步完成， 涂层可再生。这种涂层可以是中性的、带正电荷的、也可以是吸附在带正电的聚合物涂层表面转而带负电荷的。,优点,缺点 物理吸附涂层稳定性不及化学键合涂层,用于DNA分离的聚合物,交联聚合物: 交联聚丙烯酰胺、琼脂糖,非交联聚合物,均聚物,poly-N-hydroxyethylacrylamide（PHE

3、A) 存在的问题：,共聚物,a. 无规共聚物,理想的筛分介质：高筛分能力、低粘度、自涂覆功能,poly (DEA-co-DMA) 聚 (N, N -二乙基丙烯酰胺- co -N, N - 二甲基丙烯酰胺） poly (AM-co-DMA) 聚(丙烯酰胺- co - N, N - 二甲基丙烯酰胺) poly (AA-co-AG) 聚(丙烯酰胺- co - -吡喃型葡萄糖) poly(AM-co-AAG) 聚(丙烯酰胺- co -葡糖酰丙胺) poly(NEEA-co-NMEA) 聚(乙氧基乙基丙烯酰胺- co -乙氧基甲基丙烯酰胺)等,b.嵌段共聚物 PEG-(CnF2n+1)2 末端带有碳氟化

4、合物的聚乙二醇 PEO-PPO-PEO 低分子量的聚环氧乙烷和聚环氧丙烷的三嵌段共聚物 BEB/EBE 聚环氧乙烷和聚环氧丁烷的三嵌段共聚物等,C. 接枝共聚物 PAM-g-PNIPAM （聚丙烯酰胺-g- 聚N-异丙基丙烯酰胺) PNIPAM-g-PEO (聚N-异丙基丙烯酰胺-g- 聚环氧乙烷) PAM-g-PDMA （聚丙烯酰胺 -g- 聚N，N- 二甲基丙烯酰胺） PDMA-g-PMMA（聚N，N- 二甲基丙烯酰胺-g-聚甲基丙烯酸甲酯）等 存在的问题：,共混聚合物,不同分子量的PEO分离ds 和ss DNA HEC，LPA等不同分子量的混合物也都能成功地对DNA分离或排序 存在的问题

5、：,准互穿网络聚合物,Yanmei Wang,Dehai Liang, Jingcheng Hao, Dufei Fang, Benjamin Chu, Electrophoresis 2002, 23, 1460-1466,Mechanism of particle formation by inverse microemulsion polymerization of AM/AIBN system. M is monomer acrylamide; I is initiator; R is free radical.,Electrophoretic separation of DNA fr

6、agments generated on Big Dye TM Terminator Cycle Sequencing Standard with AmpliTaq FS under optimum experimental conditions: 2.5% IPNs, 200 V/cm and room temperature. A-track red, T-track blue, G-track green, and C-track black. Electrophoretic conditions were as follows: effective length 36 cm, tota

7、l length 41cm, 75-m-i.d., 365-m-o.d. anode buffer 1TTE; cathode buffer 1TTE/7M urea. The sample was injected at a constant electric field of 73 V/cm for 40 s.,Yanmei Wang, Dehai Liang, Q. Ying, B. Chu， Electrophoresis 2005, 26, 126-136,Preparation of quasi-IPN/GNPs composite matrices,quasi-IPN/GNPs复

8、合介质,TEM images of (A) GNPs20 (20 nm), (B) GNPs40 (40 nm), and (C) GNPs60 (60 nm) in water, and (D) GNPs40 (40 nm) in quasi-IPN3 polymer solution.,During the preparation of Au colloids, citrate acted as both a reducing agent and a capping agent to avoid aggregation of GNPs. The particle sizes of prep

9、ared GNPs could be controlled by the amount of trisodium citrate.,The full four-color (base C, T, A, G) electropherograms of Bigdye Terminator V 3.1 sequencing standard DNA sample by CE using 2.5% w/v quasi-IPN3/GNPs40-1 at 50. Sequencing conditions: effective/total length of bare fused-silica capil

10、laries, 50/61 cm; id/od, 75/365m; sequencing electric field strength, 150 V/cm; DNA electrokinetic injection, 41 V/cm for 30 s; anode buffer, 1TTE; cathode buffer, 1TTE/7M urea.,DNA sequencing by CE and data analysis,The partial four-color (base C, T, A, G) electropherograms of standard DNA sample u

11、sing 2.5% w/v quasi-IPN3/GNPs40-1 by CE at 50.,Electrophoresis, 2007, 28, 1072-1080.,Electrophoresis, 2007, 28, 2998-3007,中国发明专利：申请号：200610114099.3. 公开号：CN1966719A,Electrophoresis, 2008, 29, 4637-4645.,quasi-IPN/functionalized multi-walled carbon nanotubes,Schematic representation of preparation of

12、MWNT-COOH, MWNT-Br and MWNT-PDMA via ATRP,Schematic representation of the formation of quasi-IPN/MWNT-PDMA double-network composite sieving matrix.,TEM images of (A) crude MWNTs in water and (B) MWNT-PDMA in quasi-IPN solution.,Resolution vs. base number in DNA sequencing by CE using quasi-IPN, HEC HEC-g-PAM-1 HEC-g-PAM-2 HEC-g-PAM-3 HEC-g-PAM-4,Electrophoresis, 2007, 28, 3223-3231.,HEC-g-PAM,Formation of HEC-g-PAM,Viscosity versus temperature for different HEC-g-PAM copolymers.,Schematic representa