Extended Data Fig. 1: Simulation of the probability of detecting ctDNA as a function of the number of DMRs, sequencing depth and percentage of ctDNA in plasma cfDNA, and a proposed method to enrich ctDNA.
From: Sensitive tumour detection and classification using plasma cell-free DNA methylomes
a, Bioinformatic simulation of scenarios with different proportions of ctDNA present in the sample (0.001% to 10%, columns), and a range of tumour-specific DMRs—from 1, 10, 100, 1,000 or 10,000—determined through the comparison of ctDNA to normal cfDNA (rows), with reads sampled at varying sequencing depths at each locus (10×, 100×, 1,000× and 10,000×) (x axis). The probability of detecting at least five epimutations per DMR increases as the number of available features increases, even at shallow coverage per locus (left y axis). Each panel depicts probability of detection against coverage per candidate DMR for one simulation scenario. b, Schematic representation of the cfMeDIP–seq protocol.
