Figure 6

Illumina HiSeq2000 QC of one representative sample. A) Raw quality scores (FASTQ) of reads from one bisulfite treated library (G12; lane 6). B) Graph showing the representation of each base at each position in a 50 base read. Notice the very low level of Cytosine residues compared to the high content of Adenosine residues; non-bisulifte converted DNA shows approximately equal base composition at each site. One metric of C-T conversion rate is the ratio of C residues at bases 1–10 and 40–50. In the graph above, this ratio is about 1, as expected. In RRBS libraries, a large increase in Guanidine at positions 2 and 3 (~95% of reads have GG at these positions) should also be observed.