Isolation of outer membrane proteins [OMP] from Salmonella cells using zwitterionic detergent and their separation by two-dimensional electrophoresis [2-DE]

We report that using the zwitterionic detergent Zwittergent Z 3-14® to isolate outer membrane proteins (OMPs) from Salmonella O48 is suitable for their separation by two-dimensional electrophoresis (2-DE) in a capillary tube system. Sample preparation is a very crucial step for any bacterial proteomic study. Some modifications were introduced to the 2-DE protocol suggested by O'Farrell and BioRad, which significantly impaired the resolution of proteins. 2-DE analysis of OMPs may be helpful in the interpretation of the variable susceptibility of Salmonella O48 rods to the bactericidal activity of serum.