Droplet digital PCR (ddPCR) analysis of cell-free DNA (cfDNA) shows sample positive for a mutation in codon 12/13 in KRAS gene

Distribution of droplets is visualized using a heat map. Droplet thresholds are shown as pink lines. Signal detected in the channel represents DNA positive for a KRAS 12/13 mutation. Signal detected in HEX channel represents DNA positive for KRAS wild-type (WT) amplification in which cfDNA mutants were nondetectable. A. Sample positive for a mutation in codon 12/13 in KRAS gene. Distribution of negative droplets (NEG), droplets positive for mutation in KRAS codon 12/13 (KRAS 12/13+) and droplets positive for KRAS WT.