The distribution of Helicos reads is dependent on the initial denaturation temperature. Three different extracts (top: TC21c; middle: TC21b; bottom: TC21a) have been sequenced on the same Helicos run (six channels) following identical procedures, except that either mild (80°C, black) or high (95°C, gray) temperatures were used for denaturation. (Left) Read length distribution. For extracts TC21c, TC21b, and TC21a, the median read size was 29, 30, and 32 bp when DNA denaturation was performed at 80°C (black dashed lines) in contrast to 27, 29, and 29 bp at 95°C (gray dashed lines). (Middle) Read GC contents. White full lines refer to average read GC contents; the expected genomic GC content (41.4%) is reported with dashed lines. (Right) Cumulative guanine to adenine misincorporation rates as a function of the distance from sequencing start.
