High-performance liquid chromatographic method with electrochemical detection for the analysis of O-6-methylguanine

An improved system consisting of a combination of high-performance liquid c hromatographic methods with electrochemical detection for the separation an d analysis of the DNA adduct O-6-methylguanine (O6MG) has been developed. T his adduct is produced by the interaction of methylating agents with DNA an d induces mispairing in the DNA of the target cells. A good separation of m odified from unmodified bases is first achieved with an HPLC system using a Partisil 10 SCX column and a salt gradient. A second HPLC step with electr ochemical detection and a C18 column is used for farther separation and qua ntitation of O-6-methylguanine. This method shows a linear response up to 1 5 pg of O6MG tested. The lowest amount detected was 0.5 pg of O6MG and is h ighly reproducible. This method is useful to study DNA damage as a product of cellular metabolism and its effects on the process of carcinogenesis. (C ) 2001 Elsevier Science BN. All rights reserved.