CAPILLARY ELECTROPHORESIS OF DNA IN UNCROSS-LINKED POLYMER-SOLUTIONS
CAPILLARY ELECTROPHORESIS OF DNA IN UNCROSS-LINKED POLYMER-SOLUTIONS
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DOI：
10.1016/0021-9673(93)80639-p
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发表时间：
1993-10-15
影响因子：
4.1
通讯作者：
BLANCH, HW
中科院分区：
文献类型：
--
作者：
BARRON, AE;SOANE, DS;BLANCH, HW
我们使用稀释和半稀释的未交联羟乙基纤维素（HEC）溶液作为DNA限制性片段毛细管电泳的分离基质。在实验中，我们研究了羟乙基纤维素的分子量（星星）和浓度对分辨率的影响，并试图将这些参数与高分子缠结阈值浓度联系起来，由粘度-浓度数据确定了羟乙基纤维素的七种分子量组分的缠结阈值，发现缠结阈值的标度为N-1，N-2，其中N为羟乙基纤维素单体的数目。这一发现是不符合经典的缩放参数。我们提出了一个关系来预测所观察到的缠结阈值的HEC在溶液中作为数均分子量的函数，它被发现，良好的分离Phi X174/Hae III DNA限制性片段（72-1353碱基对）的HEC溶液中的毛细管电泳可以实现显着低于缠结阈值，取决于DNA的大小和HEC分子量。因此，必须重新研究这些未交联聚合物溶液中的分离机制。我们的实验表明，纠缠阈值是一个有用的参数，在预测范围内的HEC浓度，这将分离某些DNA片段，对于一个给定的HEC分子量。然而，完全纠缠网络的存在并不是分离的先决条件。
We have used dilute and semi-dilute uncross-linked hydroxyethyl cellulose (HEC) solutions as separation matrices for capillary electrophoresis of DNA restriction fragments. In these experiments, we investigated the effects of HEC molecular weight(star) and concentration on resolution, attempting to relate these parameters to the polymer entanglement threshold concentration.The entanglement thresholds of seven molecular weight fractions of hydroxyethyl cellulose were determined from viscosity-concentration data; the entanglement threshold was found to scale as N--1,N-2, where N = number of HEC monomers. This finding is not in agreement with classical scaling arguments. We present a relationship to predict the observed entanglement threshold of HEC in solution as a function of number average molecular weight.It was found that excellent separation of Phi X174/HaeIII DNA restriction fragments (72-1353 base pairs) by capillary electrophoresis in HEC solutions can be achieved significantly below the entanglement threshold, depending on DNA size and HEC molecular weight. The mechanism of separation in these uncross-linked polymer solutions must therefore be reexamined. Our experiments show that the entanglement threshold is a useful parameter in predicting a range of HEC concentrations which will separate certain DNA fragments for a given HEC molecular weight. However, the presence of a fully entangled network is not a prerequisite for separation.