Box plots of quality scores over positions in sequenced reads. Box plots of quality scores over positions in sequenced reads. Quality distributions are shown for forward reads (A), reverse reads (B), raw stitched reads (C), and filtered stitched reads (D) from a single MiSeq run. These plots are adapted from the FastQC output: the thick and thin dashed lines indicate quality scores of 20 and 28, respectively (to match the default FastQC output). André M. Comeau et al. mSystems 2017; doi:10.1128/mSystems.00127-16