Dizdaroglu M
Chemical Science and Technology Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899.
FEBS Lett. 1993 Jan 2;315(1):1-6. doi: 10.1016/0014-5793(93)81120-o.
For understanding of the role of oxidative DNA damage in biological processes such as mutagenesis and carcinogenesis, it is essential to identify and quantify this type of DNA damage in cells. This can be achieved by gas chromatography/mass spectrometry. The present study describes the quantification of modified bases in DNA by isotope-dilution mass spectrometry with the use of stable isotope-labeled analogues as internal standards. A number of isotopically labeled DNA bases were synthesized. The mass spectra of their trimethylsilyl derivatives were recorded. Calibration plots were obtained for known quantities of modified bases and their isotope-labeled analogues. Quantification of various modified DNA bases by isotope-dilution mass spectrometry was demonstrated in isolated chromatin exposed to ionizing radiation. The results indicate that gas chromatography/stable isotope-dilution mass spectrometry is an ideally suited technique for selective and sensitive quantification of modified bases in DNA.
为了解氧化DNA损伤在诸如诱变和致癌等生物过程中的作用，在细胞中鉴定和定量这类DNA损伤至关重要。这可通过气相色谱/质谱法实现。本研究描述了使用稳定同位素标记类似物作为内标，通过同位素稀释质谱法定量DNA中的修饰碱基。合成了多种同位素标记的DNA碱基。记录了它们的三甲基硅烷基衍生物的质谱。获得了已知量的修饰碱基及其同位素标记类似物的校准曲线。在暴露于电离辐射的分离染色质中，通过同位素稀释质谱法对各种修饰的DNA碱基进行了定量。结果表明，气相色谱/稳定同位素稀释质谱法是选择性和灵敏地定量DNA中修饰碱基的理想适用技术。
