Analysis of methylated circulating DNA in cancer patients' blood

Circulating extracellular nucleic acids derived from body fluids such as blood are commonly analyzed to assess malignant diseases. Efficient isolation, extraction, quantification, modification, and analysis methods remain important for utilizing circulating nucleic acids as potential molecular biomarkers. Our refined techniques of DNA isolation from serum, sodium bisulfite modification of extracted DNA, and methylation analysis provide a robust approach for quantitative analysis of circulating tumor-related DNA. The approach allows direct comparison of methylated and nonmethylated genomic sequences in a specimen.