Objective: Droplet Digital™ PCR (ddPCR™) enables the absolute quantitation of nucleic acids in a sample. Horizon Discovery's patented gene editing technology enables it to manufacture reference material that is genetically defined and validated for the allelic frequency of the mutation. These reference standards were used to test the sensitivity of Bio-Rad's QX100™ Droplet Digital™ PCR platform. Method: A panel of defined genomic DNA allelic standards and formalin fixed paraffin embedded (FFPE) cell line samples were used in this study. This panel covered EGFR (G719S, T790M, L858R and L861Q), K-Ras (codon 12) and B-Raf (V600E and V600K) mutations containing allelic frequencies between 0.05 % and 50 %. Droplet Digital™ PCR was performed using mutation specific TaqMan custom SNP assays. Results: There was a strong correlation between the predicted and actual allelic frequencies even down to 0.05 %. The allelic frequency called by the ddPCR™ platform was highly reproducible between experiments particularly in the 1-50 % dilution range.