Orientation of DNA molecules in agarose gels by pulsed electric fields.
Orientation of DNA molecules in agarose gels by pulsed electric fields.
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通过脉冲电场对琼脂糖凝胶中的 DNA 分子进行定向。
DOI：
10.1080/07391102.1985.10508418
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发表时间：
1985
影响因子：
4.4
通讯作者：
Stellwagen,NC
中科院分区：
文献类型：
--
作者：
Stellwagen,NC
测定了不同浓度琼脂糖凝胶中不同大小的622、1426和2936碱基对DNA限制性内切片段的电双折射。当凝胶的中位孔径大于溶液中DNA分子的有效水动力长度时，在凝胶中观察到的双折射弛豫时间等于在自由溶液中观察到的值。然而，如果中位孔径小于表观水动力长度，则双折射弛豫时间显著增加，与完全拉伸的DNA分子的双折射弛豫时间相等。这种明显的延伸表明，端对端迁移或重复是琼脂糖凝胶中大DNA分子电泳的可能机制。拉伸后DNA分子的弛豫时间随分子量（或等高线长度）的变化为N2.8，与重复理论基本一致。
The electric birefringence of DNA restriction fragments of three different sizes, 622,1426, and 2936 base pairs, imbedded in agarose gels of different concentrations, was measured. The birefringence relaxation times observed in the gels are equal to the values observed in free solution, if the median pore diameter of the gel is larger than the effective hydrodynamic length of the DNA molecule in solution. However, if the median pore diameter is smaller than the apparent hydrodynamic length, the birefringence relaxation times increase markedly, becoming equal to the values expected for the birefringence relaxation of fully stretched DNA molecules. This apparent elongation indicates that end-on migration, or reptation is a likely mechanism for the electrophoresis of large DNA molecules in agarose gels. The relaxation times of the stretched DNA molecules scale with molecular weight (or contour length) as N2.8, in reasonable agreement with reptation theories.