Figure 3. Elongated cells contain multiple nucleoids.

PAO1 grown in LB+0.4% NO₃ ⁻ either aerobically (A) or anaerobically (B) was stained with 10 µM Syto9, a green fluorescent dye that specifically binds to nucleic acid. Stained cells were analyzed by confocal microscopy as described in materials and methods. Simultaneously collected DIC images were shown together side by side to display the identical field of cells. Red arrows indicate the same location in a pair of cells in DIC and Syto 9 green fluorescent images.