Fig. 1: Schematic overview of droplet Tn-Seq.
From: Droplet Tn-Seq combines microfluidics with Tn-Seq for identifying complex single-cell phenotypes

a A microfluidic device encapsulates single bacterial cells into droplets containing growth medium. Bacteria are allowed to grow within droplets, genomic DNA (gDNA) is isolated at the start of the experiment (t1) and after growth (t2). Importantly, while growth for each transposon mutant takes place in isolation, gDNA is isolated from the pooled population, enabling screening of all mutants simultaneously. b gDNA is then amplified with DNA polymerase phi29, digested with MmeI, an adapter is ligated, a ~180 bp fragment is produced which contains ~16 nucleotides of bacterial gDNA, defining the transposon-insertion location, followed by Illumina sequencing. Reads are demultiplexed based on the barcode in the adapter and a potential second barcode in primer 1, mapped to the genome, and fitness is calculated for each defined region.