氯化铯梯度中DNA- Hoechst 33258（双苯甲酰胺）复合物的浮力密度：Hoechst 33258与单个AT碱基对结合。

Buoyant density of DNA-Hoechst 33258 (bisbenzimide) complexes in CsCl gradients: Hoechst 33258 binds to single AT base pairs.

作者信息

Karlovsky P, de Cock A W

机构信息

Abteilung für Molekulare Genetik Gesellschaft für Strahlen- und Umweltforschung mbH, Göttingen, Germany.

出版信息

Anal Biochem. 1991 Apr;194(1):192-7. doi: 10.1016/0003-2697(91)90167-r.

DOI:10.1016/0003-2697(91)90167-r

PMID:1714251

Abstract

Buoyant density of DNA in CsCl gradients with Hoechst 33258 (bisbenzimide) was investigated as a function of guanine plus cytosine content of the DNA (%GC; in mole percent). A formula for calculating %GC from the refractive index (nD) of the isopycnic CsCl/Hoechst 33258 solution over the range of 0-75 %GC was established: %GC = 351762.28 X nD - 123778.66 X nD2 - 249789.47 (the coefficients must not be rounded off). The shape of this curve indicates that under these conditions, in contrast to dilute buffers, Hoechst 33258 binds to single AT base pairs on DNA. Resolution of DNA bands in CsCl/Hoechst 33258 gradients is 1.6 to 2.1 times better than comparative CsCl gradients without the dye. Potential application to %GC determination is discussed.

摘要

研究了在含有 Hoechst 33258（双苯甲亚胺）的 CsCl 梯度中 DNA 的浮力密度与 DNA 中鸟嘌呤加胞嘧啶含量（%GC；摩尔百分比）的关系。建立了一个在 0 - 75%GC 范围内从等密度 CsCl/Hoechst 33258 溶液的折射率（nD）计算%GC 的公式：%GC = 351762.28×nD - 123778.66×nD² - 249789.47（系数不得四舍五入）。该曲线的形状表明，在这些条件下，与稀缓冲液不同，Hoechst 33258 与 DNA 上的单个 AT 碱基对结合。CsCl/Hoechst 33258 梯度中 DNA 条带的分辨率比不含染料的对比 CsCl 梯度高 1.6 至 2.1 倍。讨论了其在%GC 测定中的潜在应用。