Uniformity of sequence coverage. Normalized coverage is the observed coverage of each base divided by the mean coverage of all the targeted bases to allow direct comparison among the four target-enriched samples. (a) Distribution of the normalized sequence coverage. The solid lines represent the cumulative fraction of bases (left axis) for each sample. The dashed lines (right axis) show a skewed normal distribution of the coverage for each sample. (b) A scatterplot of the normalized coverage of each capture probe versus the GC content of the probe. Normalized coverage was calculated by averaging across the four samples. (c) A box-whisker plot of the normalized coverage of capture probes versus tiling-probe frequency (see Methods). Each bin from 1× to 4× contains the data of 6,007, 15,513, 27,483, 1,132, and 3,184 probes, respectively. (d) A scatterplot of the normalized coverage versus the length of each targeted Exon/ECS; the x-axis is truncated because only a handful of exons are larger than 4 kb. The solid blue lines of (c, d) represent a polynomial regression of the scatterplot.