Fig. 2

2D–plots and amount of MT-positive droplets of ddPCR results of all six patients. a All diagrams (1–6) represent merged ddPCR results of duplicates of corresponding patient samples (1–6), showing MT-positive droplet clusters (blue dots), negative droplet clusters (dark grey dots), and MT/WT-positive droplets (orange dots). The green dots represent WT-positive droplets, proving existence of cfDNA in the samples and satisfactory ddPCR conditions. Purple lines are manually placed thresholds for distinguishing positive and negative droplets, which were set at fluorescence values based on ddPCR results of FFPE samples. b The amount of MT-positive and negative droplets based on thresholds as placed in 2D–plots in (a)