Quantitative Lipopolysaccharide Analysis

LOS was analyzed via Tricine gel electrophoresis of cell lysates as described [41 (link)]. Log phase bacteria were washed with PBS, resuspended with Novex tricine SDS sample buffer (Invitrogen, 50μl 1X buffer per 0.5 OD units of bacteria), and boiled for 15 minutes. Samples were separated on Novex 16% tricine gels (Invitrogen) and stained with Pro-Q Emerald 300 (Invitrogen). Gels were imaged using UV transillumination (ChemiDoc MP). Total protein detected with subsequent Coomassie Brilliant Blue staining was used for sample normalization. Relative values were calculated by dividing each normalized LOS value by the total normalized LOS levels in WT [41 (link)].