Fig 4. Test of repeatability at the low mutant copy level—estimation of the actual number of mutant copies in each of 102 aliquots containing theoretical 1 copy of spiked mutant.

A. Histograms showing the frequency and distribution of mutant copies detected in 102 replicates for assays. B. Boxplot showing the collectively recovered number of copies by the three assays and thereby the overall detected copy number by assays. Abbreviations: EGFR, Epidermal growth factor receptor.