Supplementary Figure 2: Sequencing quality and sequencing errors (% mismatches) for control sequences.

Bar plots showing: (a) the average Phred quality score (Q) and (b) % mismatches for the 4 control sequences when sequencing with different cations Li⁺ (left), Na⁺ (middle) and K⁺ (right). c-kit, c-myc: positive controls; c-myc-opp, c-myc-mut: negative controls (see Methods). Data is taken from a number of independent sequencing experiments: 3 for Na⁺, 2 for Li⁺ and K⁺. The numbers of different control sequences (i.e. independent sequencing clusters on the flow cell) in the combined experiments are (order; c-kit, c-myc-opp, c-myc, c-myc-mut): 2741, 1139, 1040, 10945 for Li⁺; 8235, 3076, 2787, 26974 for Na⁺; 2935, 1315, 1, 12809 for K⁺. Bars are standard deviations. No error bar present for c-myc in K⁺ (n=1).