Andersson K, Hjorth R
Plasmid. 1985 Jan;13(1):78-80. doi: 10.1016/0147-619x(85)90059-9.
Plasmids extracted from bacterial cells by alkaline extraction can easily be isolated from linear DNA by isopycnic centrifugation in CsTFA. This is a fast and simple method which circumvents the use of the intercalating dye, ethidium bromide, and consequently the problems associated with its removal. The buoyant densities for covalently closed circular DNA and linear DNA in CsTFA are 1.60 g/ml and 1.65 g/ml, respectively. The isolation is achieved regardless of plasmid size and can be accomplished at temperatures of between 4 and 30 degrees C. Plasmid DNA isolated in gradients of CsTFA are of a high purity and have been found to be intact when cleaved with restriction enzymes and ligated with T4 DNA ligase.
通过碱裂解法从细菌细胞中提取的质粒，可通过在三氟乙酸铯（CsTFA）中进行等密度离心，轻松地与线性DNA分离。这是一种快速且简单的方法，避免了使用嵌入染料溴化乙锭，从而避免了与其去除相关的问题。在CsTFA中，共价闭合环状DNA和线性DNA的浮力密度分别为1.60 g/ml和1.65 g/ml。无论质粒大小如何，均可实现分离，且可在4至30摄氏度的温度下完成。在CsTFA梯度中分离得到的质粒DNA纯度很高，用限制性内切酶切割并与T4 DNA连接酶连接后，发现其保持完整。
