Measurement of Oxidative DNA Damage by Gas Chromatography-Mass Spectrometry and Liquid Chromatography-Mass Spectrometry
Oxidative DNA damage results from reactions of oxygen-derived species including free radicals, most notable hydroxyl radical, with the four heterocyclic bases and sugar moiety in DNA. A plethora of DNA products are formed comprising modified bases and sugars, DNA-protein cross-links, strand breaks, clustered lesions and tandem lesions such as 8,5'-cyclopurine 2'- deoxynucleosides. Many of these products are cytoxic, and, unless repaired by complex DNA repair mechanisms in cells, can cause cell death and mutations, and thus lead to a number of diseases. Accurate measurements are essential for the understanding of mechanisms and cellular repair of oxidative DNA damage, and its role in disease processes. The measurement of oxidative DNA damage is an enormous technical challenge because of the low levels of modifications in cellular DNA that generally consist of a few lesions among several millions of intact DNA bases. In the past, a number of analytical techniques with their own advantages and drawbacks have been used for this purpose. Some of these techniques generally measure a single compound and provide no spectroscopic evidence for identification. Mass spectrometry coupled with gas chromatography or liquid chromatography achieves unequivocal identification with structural evidence and quantification of oxidative DNA damage, and simultaneously measures a variety of DNA lesions. The application of isotope-dilution technique with the use of stable isotope-labeled analogues of DNA lesions as internal standards ascertains accurate quantification. This article reviews the measurement of oxidative DNA damage by mass spectrometric techniques. Methods for sample preparation for analysis of DNA lesions by gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry are described in detail. Possible artifact formation during sample preparation and analysis is also discussed.
derivatization, fragmentation mechanisms, gas chromatography/mass spectrometry, isotope-dilution technique, liquid chromatography/mass, oxidative DNA damage, selected-ion monitoring
Measurement of Oxidative DNA Damage by Gas Chromatography-Mass Spectrometry and Liquid Chromatography-Mass Spectrometry, Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD
(Accessed February 26, 2024)