Fig. 1

Interpulse duration (IPD) distributions from SMRT sequencing of C. elegans DNA samples. A The figure illustrates how a zero-mode waveguide monitor fluorescence signals from labeled nucleotides incorporated during DNA replication of the single-strand template of 5′-GATC-3′. The interpulse duration (IPD), the time between pulse signals from consecutive nucleosides, is useful in detecting methylated or damaged nucleotides in bacterial genomes because of slower incorporation of nucleotides by DNA polymerase. B Hexbin plot of the logarithmic scale ratio of IPD in replicate 2/WGA to IPD in replicate 1/WGA at each base for the minimum read coverage shown in the x-axis in each strand of the WGA samples. The IPDs fluctuate remarkably between the two WGA biological replicates when the minimum read coverage is low. C The frequency distribution of the IPDs in the x-axis (in log2 scale) of all bases and of individual four bases. D The y-axis of Fig. C is represented in log₁₀ scale to highlight the frequencies of high IPDs ≥2