Fig. 2

Principles of methylation pattern discovery in tissue and analyses in serum. RRBS was used in tissue samples in order to identify those CpG regions for which methylation patterns discriminate OC from other tissues, in particular blood cells which are the most abundant contaminant of cell-free DNA. An example of region #141 is provided which is a 136-bp region containing seven linked CpGs. The cancer pattern consists of reads in which all linked CpGs are methylated, indicated by “1111111” (a). b The tissue RRBS data have been processed through a bioinformatic pipeline in order to identify the most promising markers. c The principles of the serum DNA methylation assay are demonstrated