Transposon insertion site sequencing (TIS) of Pseudomonas aeruginosa

Transposon insertion site sequencing (TIS) is a technique that determines the insertion profile of a transposon mutant library by massive parallel sequencing of transposon-genomic DNA junctions. Because the transposon insertion profile reflects the abundance of each mutant in the library, it provides information to assess the fitness contribution of each genetic locus of a bacterial genome in a specific growth condition or strain background. Although introduced only about a dozen years ago, TIS has become an important tool in bacterial genetics that provides clues to study biological functions and regulatory mechanisms. Here, I describe a protocol for generating high density transposon insertion mutant libraries and preparing Illumina sequencing samples for mapping the transposon junctions of the transposon mutant libraries using Pseudomonas aeruginosa as an example.