Physical properties and gel electrophoresis behavior of R12-derived plasmid DNAs.
Physical properties and gel electrophoresis behavior of R12-derived plasmid DNAs.
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DOI：
10.1093/nar/4.5.1465
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发表时间：
1977-06
影响因子：
14.9
通讯作者：
S. Mickel;V. Arena;W. Bauer
中科院分区：
文献类型：
--
作者：
S. Mickel;V. Arena;W. Bauer
从耐药因子R12及其经溴化乙锭照射和限制性内切酶EcoRI处理得到的镍环(II)和线形(III)衍生物分别衍生出一系列闭合环状(I)质粒DNA。这些DNA的分子量在3.6到6100万吨之间。根据浮力密度测定，碱组成的范围从45%到51%(GC)。较小的质粒超螺旋(9-10%)明显少于较大的(12-13%)。在浓度为0.7%~1.6%的琼脂糖凝胶中，在0.02 M~0.08 M的电泳盐浓度范围内，测定了三种DNA结构形式的凝胶电泳性与分子质量的关系。DNA I和DNA III的迁移率在分子量上发生相对于彼此的反转，随着琼脂糖凝胶浓度的增加而降低。DNA II不能进入凝胶的分子量取决于电泳过程中的离子强度，而不是凝胶浓度。
A series of closed circular (I) plasmid DNAs has been derived from drug resistance factor R12, and the nicked circular (II) and linear (III) derivatives of these molecules prepared by irradiation in the presence of ethidium bromide and by treatment with restriction enzyme EcoRI, respectively. These DNAs encompass the molecular weight range 3.6 to 61 megadaltons. The base compositions range from 45% to 51% (GC) as estimated by buoyant density determinations. The smaller plasmids are significantly less supercoiled (9-10%) than are the larger (12-13%). The gel electrophoretic behavior of the three DNA structural forms was determined as a function of molecular weight in agarose gels of concentrations ranging from 0.7% to 1.6% and at electrophoresis salt concentrations from 0.02 M to 0.08 M sodium acetate. The mobilities of DNAs I and III undergo a reversal relative to each other at a molecular weight which decreases with increasing agarose gel concentration. The molecular weight at which DNA II fails to enter a gel depends upon the ionic strength during electrophoresis but not upon the gel concentration.