Fig. 2

Correlation between observed and expected mutant counts. The red line shows a 1:1 ratio and the black line shows the true relationship between expected and observed mutant count. The plot shows that mutants with low counts cannot be accurately quantified. This results in a non-linear relationship between expected and observed mutant count (P < 0.0001). Hence, a limit of detection/linear model was used to adjust the total mutation counts of each independent mutation