Fig. 4.

Detection of BRAF D594G mutation by ddPCR.

A) Limit of blank (LOB) determination for 20 ng DNA samples. 16-replicate wells of wild type-only template were run. Droplets are classified as wild type-only (green), mutant-only droplets (blue) double wild type-mutant droplets (orange) and double negative (grey). The LOB was set at 0.15% and 0.18% for 20 and 6 ng samples, respectively. B) Limit of detection (LOD) determination for DNA amounts of 20 (upper) and 6 ng (lower). Log of MAF values was used to calculate correlation between expected and detected MAFs (R²). Confidence interval for LOB is shown in grey. Based on obtained values (table), LOD was determined as 0.5% and 1% for 20 and 6 ng, respectively. C) MAF observed for tested tissue and cfDNA samples. Abbreviations: cfDNA – cell-free DNA; MAF – mutant allele fraction. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)