Method: A panel of X-Man™ (gene-X, Mutant And Normal) cell lines were developed using our patented gene editing technology (GENESIS™) including; B-Raf V600E, V600K; EGFR ΔE746-A750, T790M, L858R, L861Q; K-Ras G12A, G12C, G12D, G12R, G12S, G12V, G13D; PI3Kα E542K, E545K, H1047R. FFPE blocks containing specific allelic frequencies including: 50 %, 33 %, 25 %, 20 % or 5 % were generated and sections cut. DNA was extracted using five different extraction methods and analysed using Droplet Digital™ PCR. Results: Mutant alleles could be detected using Droplet Digital™ PCR at each defined allelic frequency and the reproducibility of each test was very high. The allelic frequency was consistent throughout each block. The total DNA yield from each section was consistent using the same extraction method but varied between methods.