Fig. 1.

Schematic workflow of MeD-seq on cfDNA. A The LpnPI endonuclease recognizes methylated CpG motifs and incises the DNA 16 bp upstream and downstream to generate 32 bp fragments. B After adaptor ligation, size fractionation is performed using the Pippin HT platform. C All fragments of the selected size are amplified by PCR and sequenced. Only fragments with a CpG on the central position pass the filter and are considered as methylated reads. Green: LpnPI endonuclease, black tabs: CpG-site, red circles: CpG methylation