TEM Imaging

A secondary culture of P. aeruginosa (strain PA14) was grown to OD₆₀₀ −0.5. Bacteria was washed twice with PBS and 1 × 10⁶ cfu was aliquoted and pelleted in 1.5 cc Eppendorf tubes. Bacteria was then resuspended in 100 μL PBS (control) or a solution of Am-Dextran 40 (1 μM), free WLBU2 peptide (5 μM), or WD40 (5 μM). After 5 min incubation, bacteria were pelleted by centrifugation (2000 rcf for 5 min) and supernatant was removed. The bacteria pellet was then fixed in glutaraldehyde and subsequently dehydrated with acetone. After embedding in epoxy resin, ultrathin sections were placed on Formvar-coated grids and stained with 3% uranyl acetate. Sections were imaged using the FEI Technai Spirit transmission electron microscope.