Chronic respiratory infections with the ubiquitous, gram-negative bacterium Pseudomonas aeruginosa has been implicated as the leading cause of morbidity and mortality in patients with cystic fibrosis (CF). Research in the Boucher laboratory centers around the analysis of proteins localized to the P. aeruginosa outer membrane. P. aeruginosa, as well as other bacteria, are protected from the environment via an outer membrane (OM). To date, there are a number of OM proteins that have been identified for P. aeruginosa. However, the exact number and function of all the P. aeruginosa outer membrane proteins remain unknown. The questions I’m addressing are: (I) how many additional proteins to those already identified are there in the P. aeruginosa OM?, and (ii) is there a particular outer membrane protein that may be higher in concentration in P. aeruginosa strains chronically infecting CF patients?. In order to answer these questions a number of proteomic and genomic approaches are currently being used.