Sequencing quality control and reproducibility. Panel A shows quality scores of the Illumina sequencing reads for mapping. Fifty base pair single-end reads were obtained with ‘high’ quality out to ~42 base pairs and ‘good’ quality out to ~47 base pairs. The green background corresponds to high quality reads, the yellow background to intermediate quality reads and the red background to poor quality reads. Data shown are for the number of high, intermediate and low quality reads at a specific number of base pairs away from the transposon. The yellow bar encompasses the 25-75th percentile and the red horizontal bar indicates the mean. The green bracket identifies the base pair position where high quality reads comprise the over 75% of the total reads. Blue arrow signifies where typical amount of sequencing that can be obtained when preparing DNA using the MmeI restriction site, demonstrating superior mapping and analysis ability of C-tailing method. No sequencing reads shorter than 20 bp were used for analyses. B) Replicates of the same library were sequenced in separate experiments. The graph compares the number of insertions per gene for technical replicates 1 and 2 of P. gingivalis strain ATCC 33277 Mariner mutant library and showed excellent correlation between the replicates (R2=0.9892). Median number of insertions when excluding genes containing zero is 9 while the mean is 17. Sixteen genes have 100 insertions or greater.