该文利用一种基于原子力显微镜(AFM)抬高模式(Lift mode)的"逐线反馈纳米操纵"技术成功地进行了DNA单分子水平上的切割、拾取及连接酶分子的传递,系统地完成了DNA的分子手术。在切割和拾取过程中,以PBR322/Pst I DNA为研究对...该文利用一种基于原子力显微镜(AFM)抬高模式(Lift mode)的"逐线反馈纳米操纵"技术成功地进行了DNA单分子水平上的切割、拾取及连接酶分子的传递,系统地完成了DNA的分子手术。在切割和拾取过程中,以PBR322/Pst I DNA为研究对象,进行了单分子水平上的切割,实验发现由于DNA分子本身弹性,切割过程极易出现切割端变粗的现象。在分子传递过程中,分别以T4 DNA连接酶和小牛胸腺组蛋白分子为研究对象,实现针尖和基底表面之间的分子传递。同时通过控制针尖运动成功获得连接酶分子点阵排列及小牛胸腺组蛋白方块状纳米结构。结果表明利用此操纵方法可以获得很高的精确度,切割DNA时的空间精确度小于5 nm。系列单分子水平上的分子手术的整合为实现单分子水平上生化反应,甚至构造智能机器提供了可能。展开更多
将生物素标记的DNA与链霉亲和素(streptavidin,STV)按4∶1摩尔比连接,用原子力显微镜(atomic force microscope,AFM)对混合物表征,观察到所有可能的几种DNA-STV复合物。并按照不同摩尔浓度比和孵育时间配制DNA与STV混合液,探讨了影响结...将生物素标记的DNA与链霉亲和素(streptavidin,STV)按4∶1摩尔比连接,用原子力显微镜(atomic force microscope,AFM)对混合物表征,观察到所有可能的几种DNA-STV复合物。并按照不同摩尔浓度比和孵育时间配制DNA与STV混合液,探讨了影响结合效率的因素,初步得到用生物素-链霉亲和素系统批量制备1STV-1DNA单分子复合物的最佳制备条件,为未来单分子DNA的大规模快速制备奠定了基础。展开更多
DNA and histone protein are important in the formation of nucleosomal arrays, which are the first packaging level of DNA into a more compact chromatin structure. To characterize the interactions of DNA and histone pro...DNA and histone protein are important in the formation of nucleosomal arrays, which are the first packaging level of DNA into a more compact chromatin structure. To characterize the interactions of DNA and histone proteins, we reconstitute nucleosomes using lambda DNA and whole histone proteins by dialysis and perform direct atomic force microscopy （AFM） imaging. Compared with non-specific DNA and histone binding, nucleosomes are formed within the assembled “beads-on-a-string” nucleosomal array by dialysis. These observations facilitate the establishment of the molecular mechanisms of nucleosome and demonstrate the capability of AFM for protein-DNA interaction analysis.展开更多
Nano-manipulation of single atoms and molecules is a critical technique in nanoscience and nanotech- nology. This review paper will focus on the recent development of the manipulation of single DNA molecules based on ...Nano-manipulation of single atoms and molecules is a critical technique in nanoscience and nanotech- nology. This review paper will focus on the recent development of the manipulation of single DNA molecules based on atomic force microscopy (AFM). Precise manipulation has been realized including varied manipulating modes such as “cutting”, “pushing”, “folding”, “kneading”, “picking up”, “dipping”, etc. The cutting accuracy is dominated by the size of the AFM tip, which is usually 10nm or less. Single DNA fragments can be cut and picked up and then amplified by single molecule PCR. Thus positioning isolation and sequencing can be performed.展开更多
Nanopores have been studied as a unique DNA sequencing technology that can quickly read long stretched DNA sequences. A DNA molecule could pass through a nanopore in a speed of microsecond per base and even faster. Wi...Nanopores have been studied as a unique DNA sequencing technology that can quickly read long stretched DNA sequences. A DNA molecule could pass through a nanopore in a speed of microsecond per base and even faster. With this speed, a human genome can potentially be sequenced by one nanopore in 〈1 h. In contrast to next- generation DNA sequencing （NGS）, the nanopore sequencing is enzyme free without need of sample amplification due to its single-molecule nature. The nanopore sequencing has been envisioned as a new generation of DNA sequencing technology in the post-NGS era. This progress focuses on status quo of the nanopore DNA sequencing and discusses the opportunities and challenges in this rapidly growing field.展开更多
We are all familiar with DNA as the substance that encodes the genomes of all living things.In addition to genetic function,DNA is one of the smartest building blocks for innovative nanostructures.DNA walker is a kind...We are all familiar with DNA as the substance that encodes the genomes of all living things.In addition to genetic function,DNA is one of the smartest building blocks for innovative nanostructures.DNA walker is a kind of self-assembled molecular machine that mimics the movement of protein motors in living systems.Usually,DNA walker consists of three parts：a single stranded DNA track,展开更多
The capability to image, as well as control and manipulate single molecules such as nucleic acids(DNA or RNA) can greatly enrich our knowledge of the roles of individual biomolecules in cellular processes and their be...The capability to image, as well as control and manipulate single molecules such as nucleic acids(DNA or RNA) can greatly enrich our knowledge of the roles of individual biomolecules in cellular processes and their behavior in native environments. Here we summarize the recent advances of single nucleic acid imaging based on optical observation and force manipulation. We start by discussing the superiority of single molecule image, the central roles nucleic acids play in biosystems, and the significance of single molecule image towards nucleic acids. We then list a series of representative examples in brief to illustrate how nucleic acid of various morphologies has been imaged from different aspects, and what can be learned from such characterizations. Finally,concluding remarks on parts of which should be improved and outlook are outlined.展开更多
Single molecule detection based on nanopore technology is a very promising approach for medical diagnostics, drug therapy and even DNA sequencing. Compared with other biological nanopores and solid-state nanopores, th...Single molecule detection based on nanopore technology is a very promising approach for medical diagnostics, drug therapy and even DNA sequencing. Compared with other biological nanopores and solid-state nanopores, the glass capillary nanopore has low cost, easy availability and stable mechanical characteristics, thus it has been widely used in the nanopore technology for single molecule detection. In this review, we will focus on the studies of the glass nanopore sensors. The popular glass nanopore fabrication methods would be introduced, and the applications of glass nanopores in the detection of nanoparticles, proteins and DNA molecules would be presented. We hope this review will help widen field of vision and promote the development of the nanopore technology based on the glass capillary nanopores.展开更多
文摘将生物素标记的DNA与链霉亲和素(streptavidin,STV)按4∶1摩尔比连接,用原子力显微镜(atomic force microscope,AFM)对混合物表征,观察到所有可能的几种DNA-STV复合物。并按照不同摩尔浓度比和孵育时间配制DNA与STV混合液,探讨了影响结合效率的因素,初步得到用生物素-链霉亲和素系统批量制备1STV-1DNA单分子复合物的最佳制备条件,为未来单分子DNA的大规模快速制备奠定了基础。
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.11274374）, the National Basic Research Program of China （No.2009CB930704）, and the Basic Scientific Research Foundation of China Agricultural University （No.2012QJ026）.
文摘DNA and histone protein are important in the formation of nucleosomal arrays, which are the first packaging level of DNA into a more compact chromatin structure. To characterize the interactions of DNA and histone proteins, we reconstitute nucleosomes using lambda DNA and whole histone proteins by dialysis and perform direct atomic force microscopy （AFM） imaging. Compared with non-specific DNA and histone binding, nucleosomes are formed within the assembled “beads-on-a-string” nucleosomal array by dialysis. These observations facilitate the establishment of the molecular mechanisms of nucleosome and demonstrate the capability of AFM for protein-DNA interaction analysis.
文摘Nano-manipulation of single atoms and molecules is a critical technique in nanoscience and nanotech- nology. This review paper will focus on the recent development of the manipulation of single DNA molecules based on atomic force microscopy (AFM). Precise manipulation has been realized including varied manipulating modes such as “cutting”, “pushing”, “folding”, “kneading”, “picking up”, “dipping”, etc. The cutting accuracy is dominated by the size of the AFM tip, which is usually 10nm or less. Single DNA fragments can be cut and picked up and then amplified by single molecule PCR. Thus positioning isolation and sequencing can be performed.
基金supported by the National Natural Science Foundation of China (21372183)the Hubei Province Natural Science Foundation (2013CFB328)+1 种基金the Key Laboratory of Analytical Chemistry for Biology and Medicine (Wuhan University), Ministry of Education (ACBM2014001)the Start-Up-Fund grant provided by Wuhan University of Science and Technology
文摘Nanopores have been studied as a unique DNA sequencing technology that can quickly read long stretched DNA sequences. A DNA molecule could pass through a nanopore in a speed of microsecond per base and even faster. With this speed, a human genome can potentially be sequenced by one nanopore in 〈1 h. In contrast to next- generation DNA sequencing （NGS）, the nanopore sequencing is enzyme free without need of sample amplification due to its single-molecule nature. The nanopore sequencing has been envisioned as a new generation of DNA sequencing technology in the post-NGS era. This progress focuses on status quo of the nanopore DNA sequencing and discusses the opportunities and challenges in this rapidly growing field.
文摘We are all familiar with DNA as the substance that encodes the genomes of all living things.In addition to genetic function,DNA is one of the smartest building blocks for innovative nanostructures.DNA walker is a kind of self-assembled molecular machine that mimics the movement of protein motors in living systems.Usually,DNA walker consists of three parts：a single stranded DNA track,
基金supported by the National Natural Science Foundation of China (21525523, 21574048, 21375042, 21405054)the National Basic Research Program of China (2015CB932600, 2013CB933000)+1 种基金the Special Fund for Strategic New Industry Development of Shenzhen, China (JCYJ20150616144425376)1000 Young Talent (to Fan Xia)
文摘The capability to image, as well as control and manipulate single molecules such as nucleic acids(DNA or RNA) can greatly enrich our knowledge of the roles of individual biomolecules in cellular processes and their behavior in native environments. Here we summarize the recent advances of single nucleic acid imaging based on optical observation and force manipulation. We start by discussing the superiority of single molecule image, the central roles nucleic acids play in biosystems, and the significance of single molecule image towards nucleic acids. We then list a series of representative examples in brief to illustrate how nucleic acid of various morphologies has been imaged from different aspects, and what can be learned from such characterizations. Finally,concluding remarks on parts of which should be improved and outlook are outlined.
基金supported by the National Basic Research Program of China("973"Project)(Grant No.2011CB707605)National Natural Science Foundation of China(Grant No.51375092)+1 种基金the support by the Fundamental Research Funds for the Central Universities(Grant No.2242015R30002)supported by the Fundamental Research Funds for the Central Universities and the Innovative Project for Graduate Students of Jiangsu Province(Grant No.KYLX_0100)
文摘Single molecule detection based on nanopore technology is a very promising approach for medical diagnostics, drug therapy and even DNA sequencing. Compared with other biological nanopores and solid-state nanopores, the glass capillary nanopore has low cost, easy availability and stable mechanical characteristics, thus it has been widely used in the nanopore technology for single molecule detection. In this review, we will focus on the studies of the glass nanopore sensors. The popular glass nanopore fabrication methods would be introduced, and the applications of glass nanopores in the detection of nanoparticles, proteins and DNA molecules would be presented. We hope this review will help widen field of vision and promote the development of the nanopore technology based on the glass capillary nanopores.
