Figure 1

Base quality scores at error positions. Quality scores of bases were collected at error positions and plotted in boxplot format (quartiles) per run, compared with the quality scores of a five base neighborhood surrounding the error position. Base quality scores of the neighborhood show a tendency of higher values than the actual error position. Runs 1-3 were performed with the same bead pool, the quality scores of these three runs show no significant differences, runs 5 and 6 were enriched manually and differ significantly. The asterisks mark the overall quality of the particular sequencing run.