All cells in the body release DNA by apoptosis/necrosis into the bloodstream, referred to as circulating cell-free DNA (cfDNA). cfDNA “real-time” biomarkers are becoming popular in disease screening, diagnostics, and surveillance trough “minimally-invasive liquid biopsies” (i.e. blood samples).
A significant challenge for the clinical utilization of cfDNA as a biomarker is the small size of cfDNA (~167 bp) and the very limited amount present in blood samples, compared to traditional biomarkers. This has required establishment of alternative, more efficient strategies for cfDNA purification and application of ultrasensitive detection methods, such as digital droplet PCR. However, few efforts have focused on ensuring high recovery and high efficiency during the bisulphite conversion of cfDNA required for application of methylation-based biomarkers.
To identify the most suited method for bisulfite conversion of cfDNA, we directly compared 13 different methods in regard to conversion efficiency, recovery of cfDNA after conversion and overall performance.