DNA molecules descending a nanofluidic staircase by entropophoresis.
DNA molecules descending a nanofluidic staircase by entropophoresis.
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DNA 分子通过电泳沿着纳米流体阶梯下降。
DOI：
10.1039/c2lc21152a
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发表时间：
2012
期刊：
影响因子：
6.1
通讯作者：
E. Strychalski
中科院分区：
文献类型：
--
作者：
S. Stavis;J. Geist;M. Gaitan;L. Locascio;E. Strychalski
第一次设计了受限DNA分子的复杂熵梯度。根据热力学第二定律，这使得DNA分子能够定向自我运输和自我浓缩。这种新的纳米流体方法被称为熵电泳。如在实验中所实施的，长DNA分子用花青二聚体染色，分散在高离子强度缓冲液中，并被具有近似于阶梯函数的深度分布的纳米流体通道限制。阶梯深度跨越了从强约束到中等约束的过渡。DNA分子在狭缝状台阶上的扩散被施加在台阶边缘的熵力所棘轮化，使得DNA分子下降并收集在楼梯的底部，如通过荧光显微镜所观察到的。不同的DNA形态，长度，和化学计量的碱基对染料分子的比例进行了测试，并确定通过电泳的运输速率的影响。棘轮扩散模型被用来解释一个复杂的自由能景观中的标准长度的线性DNA分子的力的平衡转移。开发了内电泳的整体性能和最佳性能的相关指标。这里报道的装置和方法超越了纳米流体的当前限制，并在聚合物物理学、生物物理学、分离科学和芯片实验室技术中呈现了新的可能性。
A complex entropy gradient for confined DNA molecules was engineered for the first time. Following the second law of thermodynamics, this enabled the directed self-transport and self-concentration of DNA molecules. This new nanofluidic method is termed entropophoresis. As implemented in experiments, long DNA molecules were dyed with cyanine dimers, dispersed in a high ionic strength buffer, and confined by a nanofluidic channel with a depth profile approximated by a staircase function. The staircase step depths spanned the transition from strong to moderate confinement. The diffusion of DNA molecules across slitlike steps was ratcheted by entropic forces applied at step edges, so that DNA molecules descended and collected at the bottom of the staircase, as observed by fluorescence microscopy. Different DNA morphologies, lengths, and stoichiometric base pair to dye molecule ratios were tested and determined to influence the rate of transport by entropophoresis. A model of ratcheted diffusion was used to interpret a shifting balance of forces applied to linear DNA molecules of standard length in a complex free energy landscape. Related metrics for the overall and optimum performance of entropophoresis were developed. The device and method reported here transcend current limitations in nanofluidics and present new possibilities in polymer physics, biophysics, separation science, and lab-on-a-chip technology.
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影响因子：
10.8
作者：
Levy SL;Mannion JT;Cheng J;Reccius CH;Craighead HG
通讯作者：
Craighead HG
使用纳米狭缝阵列非平衡分离短 DNA。
影响因子：
3.2
作者：
Strychalski,ElizabethA;Lau,HenryW;Archer,LyndenA
通讯作者：
Archer,LyndenA
影响因子：
7.4
作者：
Cabodi, M;Turner, SWP;Craighead, HG
通讯作者：
Craighead, HG
影响因子：
56.9
作者：
Han, J;Craighead, HG
通讯作者：
Craighead, HG
影响因子：
7.4
作者：
Leslie, Sabrina R.;Fields, Alexander P.;Cohen, Adam E.
通讯作者：
Cohen, Adam E.