Detection of polymorphism in the methlyenetetrahydrofolate reductase gene by Raman spectroscopy

A novel approach using micro-Raman spectroscopy for the detection of alteration of global DNA methylation levels in human individuals with polymorphism in the methlyenetetrahydrofolate reductase (MTHFR) gene was tested. Comparison of measured Raman spectra from samples with wild type genotype to those with polymorphism (homozygous and heterozygous) in the MTHFR gene revealed that the intensity of the ∼ 2945 cm^-1 peak, representing C-H stretches in the DNA constituents and in the methyl group is sample dependent. The intensity ratios between the area of these peaks in the different samples and the peaks at 1667 cm^-1 were used to assess the extent of methylation, allowing classification of the DNA samples for the common MTHFR polymorphism, MTHFR 677 C > T. These results suggest that improvement of the identification capabilities of Raman spectroscopy for DNA methylation can contribute to disease diagnosis and to a better understanding of the physical and biomolecular processes related to epigenetic regulation of the genome.