Entropic recoil separation of long DNA molecules
Entropic recoil separation of long DNA molecules
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DOI：
10.1021/ac025879a
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发表时间：
2002-10-15
影响因子：
7.4
通讯作者：
Craighead, HG
中科院分区：
文献类型：
--
作者：
Cabodi, M;Turner, SWP;Craighead, HG
提出了一种根据长度快速分离长链聚合物的新技术。分离机制是介导的约束诱导的熵力在急剧的界面之间的区域有很大的不同的配置熵。为了证明这种技术，使用脉冲电场将DNA分子部分插入到密集的纳米柱阵列（熵不利区域）中，并通过去除电场使其松弛到其自然状态。不同长度的分子（T2和T7大肠杆菌噬菌体DNA）被插入到该区域中，以这样的方式，较短的分子被完全插入到该区域中，而较长的分子保持部分穿过界面。观察到较长的T2分子完全从柱阵列中弹回，留下较短的T7分子插入，并在单个步骤中实现两种物质的分离。为了展示这种方法如何用于分离未知样品，插入电场脉冲时间逐渐变长，允许逐渐变长的分子通过，并产生相当于传统电泳图的结果。限制在此设备的分辨率的影响进行了讨论，并报告了多级设备的预期分离功率。所提取的分辨率和运行分离时间与当前常规分离技术相比毫不逊色。
A novel technique that can rapidly separate long-strand polymers according to length is presented. The separation mechanism is mediated by a confinement-induced entropic force at the abrupt interface between regions of vastly different configuration entropy. To demonstrate this technique, DNA molecules were partially inserted into a dense array of nanopillars (an entropically unfavorable region) using a pulsed electric field and allowed to relax to their natural state by removal of the field. Molecules of dissimilar lengths (T2 and T7 coliphage DNA) were inserted into this region in such a way that shorter molecules were fully inserted in this region, while longer molecules remained partially across the interface. The longer T2 molecules were observed to recoil entirely out of the pillar array, leaving the shorter T7 molecules inserted, and effecting separation of the two species in a single step. To show how this method can be used for separation of unknown samples, the inserting electric field was pulsed for progressively longer times, allowing passage of progressively longer molecules and producing the equivalent of a conventional electropherogram. The effects limiting resolution in this device are discussed, and the expected separating power of a multistage device is reported. The extracted resolution and running separation time compare favorably with current conventional separation techniques.