Escherichia coli KEIO_ML9 RB-Tn library  in monoculture; replicate B
Using  purified gDNA from experimental samples as template, transposon barcodes were  amplified using the previously described BarSeq98 protocol and primers, which  add a unique experimental index to each sample to enable multiplex sequencing  (Wetmore et al. 2015). Equimolar concentrations of PCR product from all 13  samples were pooled. The pooled PCR products were purified using Agencourt  AMpure beads (Beckman Coulter) and then sequenced using standard sequencing  primers on a single Illumina NextSeq 75 cycle high-output run.