In spite of the significant progresses in the field of replaceable sieving matrices for separating DNA in capillary electrophoresis (CE), an intense research activity is still going on to improve the separation of large size DNA sequencing fragments. There are evidences, both from experimental and theoretical sides that the resolution of these fragments, at the single base, requires the use of sieving matrices comprised of long chain linear polymers. In the separation of DNA fragments by CE are of upmost importance: (i) the complete solubility of the polymer, (ii) the linearity of the chain, (iii) the achievement of ultrahigh viscosity in dilute solutions. The aim of this work is the synthesis of ultrahigh-molecular-weight polymers which possess the three requirements mentioned above by employing a nonconventional method. We demonstrate that the sieving performance of polyacrylamide is directly correlated to its intrinsic viscosity. 相似文献
The combination of polymers with nucleic acids leads to materials with significantly advanced properties. To obviate the necessity and complexity of conjugating two macromolecules, a polymer initiator is described that can be directly covalently linked to DNA during solid‐phase synthesis. Polymer can then be grown from the DNA bound initiator, both in solution after the DNA‐initiator is released from the solid support as well as directly on the solid support, simplifying purification. The resulting polymer‐DNA hybrids were examined by chromatography and fluorescence methods that attested to the integrity of hybrids and the DNA. The ability to use DNA‐based supports expands the range of readily available molecules that can be used with the initiator, as exemplified by direct synthesis of a biotin polymer hybrid on solid‐support. This method expands the accessibility and range of advanced polymer biohybrid materials. 相似文献
A novel separation medium, hydroxyethylcellulose-graft-polyacrylamide (HEC-g-PAM) synthesized by atom transfer radical polymerization (ATRP), used for dsDNA separation by CE is presented. The separation performance of HEC-g-PAM, which has the same graft density and different graft length, has been investigated in Tris-boric acid-EDTA (TBE) buffer solvent mixtures. The temperature-dependent rheological behavior of HEC-g-PAM was also studied by steady-shear rheometry. The results showed that dsDNA fragments between 72 and 1353 bp was achieved with a 30 cm effective capillary length at 150 V/cm using this type of graft copolymer as a separation medium in bare fused-silica capillaries, and separation improvement is obtained in HEC-g-PAM compared with HEC and poly(dimethylacrylamide (PDMA). 相似文献
Monodentate DNA binding of [PtCl(dien)]+ (dien=diethylenetriamine) complexes may considerably affect the biophysical properties of DNA and consequently downstream cellular processes as a result of a large increase in the bulkiness of the nonleaving ligand by multiple methylation (see illustration).
Conjugation of a hydrophobic poly(2‐oxazoline) bearing tertiary amide groups along its backbone with a short single stranded nucleotide sequence results in an amphiphilic comb/graft copolymer, which organizes in fibrils upon direct dissolution in water. Supported by circular dichroism, atomic force microscopy, transmission electron microscopy, and scattering data, fibrils are formed through inter‐ and intramolecular hydrogen bonding between hydrogen accepting amide groups along the polymer backbone and hydrogen donating nucleic acid grafts leading to the formation of hollow tubes.
Quasi-interpenetrating network (IPN) formed by polyacrylamide and poly(N,N-dimethylacrylamide) was designed, synthesized, and tested as a high-performance DNA separation medium by capillary electrophoresis. The performance of quasi-IPN on DNA sequencing was determined by the acrylamide to dimethylacrylamide molar ratio, polyacrylamide molecular weight, and its size distribution. Under optimal operating conditions, quasi-IPN was able to achieve one-color DNA sequencing up to 1000 bases in 39 min, or 1200 bases in 60 min. Its performance was compared with some of the existing commercialized products, such as POP6 from Applied Biosystems and MegaBACE matrix from Amersham Biosciences. By using the ABI 310 Genetic Analyzer, even without optimized base-calling software, quasi-IPN yielded a read length of up to 700 bases of contiguous sequence (50-750 bases) in 35 min with 99.6% accuracy, or 750 bases of contiguous sequence (50-800 bases) in 37 min with 98.0% accuracy. 相似文献
This review article describes the preparation of polymer brushes by nitroxide‐mediated radical polymerization using either the ‘grafting to’ or the ‘grafting from’ approach. The use of TEMPO as a classical initiator is intensively described. More sophisticated nitroxides are also included in the discussion. Brush formation on flat surfaces such as wafers and also on particles is reported. Finally, some applications of polymer brushes are presented.
DNA charge transfer chemistry has been subject of considerable interest with consequences in the formation of oxidative damage to the DNA which can result in mutagenesis or carcinogenesis. In this article, important examples of spectroscopical and biochemical assays are compared and discussed in terms of the effiencies, rates, and mechanisms. Coupled with the demonstration that such charge transfer can be modulated both negatively and positively by DNA‐binding proteins, these observations therefore suggest the intriguing possibility that DNA‐mediated charge transfer chemistry is biological relevant and may play a role in cellular processes. Additionally, charge transfer chemistry plays a growing role in the recent development of DNA chips detecting mutations or lesions of nucleic acids. 相似文献
Click chemistry, one of the most important methods in conjugation, plays an extremely significant role in the synthesis of functional aliphatic polycarbonates, which are a group of biodegradable polymers containing carbonate bonds in their main chains. To date, more than 75 articles have been reported on the topic of click chemistry in functional aliphatic polycarbonates. However, these efforts have not yet been highlighted. Six categories of click reactions (alkyne‐azide reaction, thiol‐ene reaction, Michael addition, epoxy‐amine/thiol reaction, Diels‐Alder reaction, and imine formation) that have been afforded for further post‐polymerization modification of polycarbonates are reviewed. Through this review, a comprehensive understanding of functional aliphatic polycarbonates aims to afford insight on the design of polycarbonates for further post‐polymerization modification via click chemistry and the expectation of the practical application. 相似文献
It is demonstrated that bifunctionalized polythiophenes involving thiol and azide end‐functional groups can be synthesized by chain‐growth Suzuki‐Miyaura type polymerization. The bifunctionalized polythiophenes are successfully characterized by 1H NMR, gel permeation chromatography (GPC), and matrix‐assisted laser desorption ionization time‐of‐flight (MALDI‐TOF). Furthermore, the azide end‐group reacts with DNA via “click chemistry” to form a polythiophene/DNA hybrid structure, which is characterized by ESI‐MS. The described synthetic approaches will lead to the synthesis of novel multi‐block copolymers as well as biomolecule‐based conjugated polymer structures. 相似文献