Anchordoquy T J, Molina M dC, Kempner E S
School of Pharmacy, University of Colorado Health Sciences Center, Denver, CO 80262, USA.
Anal Biochem. 2009 Feb 15;385(2):229-33. doi: 10.1016/j.ab.2008.10.049. Epub 2008 Nov 11.
Supercoiled DNA plasmids were exposed in the frozen state to high-energy electrons. Surviving supercoiled molecules were separated from their degradation products (e.g., open circle and linear forms) by agarose gel electrophoresis and subsequently quantified by staining and image analysis. Complex survival curves were analyzed using radiation target theory, yielding the radiation-sensitive mass of each form. One of the irradiated plasmids was transfected into cells, permitting radiation analysis of gene expression. Loss of this function was associated with a mass much smaller than the entire plasmid molecule, indicating a lack of energy transfer in amounts sufficient to cause structural damage along the DNA polynucleotide. The method of radiation target analysis can be applied to study both structure and function of DNA.
超螺旋DNA质粒在冷冻状态下暴露于高能电子。通过琼脂糖凝胶电泳将存活的超螺旋分子与其降解产物（如开环和线性形式）分离，随后通过染色和图像分析进行定量。使用辐射靶理论分析复杂的存活曲线，得出每种形式的辐射敏感质量。将其中一个受辐照的质粒转染到细胞中，从而对基因表达进行辐射分析。这种功能的丧失与一个比整个质粒分子小得多的质量相关，表明缺乏足以沿DNA多核苷酸造成结构损伤的能量转移量。辐射靶分析方法可用于研究DNA的结构和功能。
