Improved quality of whole-genome bisulfite sequencing (WGBS) with Kineococcus radiotolerans used as a spike-in. The plot shows the proportion of reads at or above a quality score of 30 for read 1 (left) and read 2 (right). The pink lines show the performance of K. radiotolerans (G + C = 0.74) added at a proportion of 17.9% (light pink) or 5.3% (dark pink), and PhiX (G + C = 0.44, green). The results are plotted to show the quality for C/G (solid lines) separately from other nucleotides (dotted lines), as the performance of WGBS is especially problematic for C/G nucleotides, a fact missed by plots that do not separate out these nucleotides. The high (G + C) K. radiotolerans spike-in, even at 5.3% proportion, restores C/G quality to levels comparable with the other nucleotides.
