A simple, highly selective, and sensitive method has been developed to quantify methylation of DNA extracted from human peripheral blood mononuclear cells. Assay has been performed at nucleobases level. Cytosine and 5-methylcytosine DNA content has been detected by gas chromatography-mass spectrometry using [2- 13C]cytosine and [2- 13C]5- methylcytosine as internal standards. The methylation level has been calculated as 5-methylcytosine/total cytosine ratio. The working range selected on calibration curve, obtained by evaluation of standards and matrix-added standards measurements, is suitable for 5 μg DNA analysis. In this range, healthy human DNA methylation percentage is within 5-6%.
- DNA methylation
- Gas chromatography-mass spectrometry
- Stable isotopes
ASJC Scopus subject areas
- Molecular Biology