Tie pfs inverted epifluorescence microscope

For fluorescence microscopy, cells were grown anaerobically to mid-exponential phase at 28 °C. Living cells are then shifted in buffer and 2 μl was mounted on microscope slide and coverslip. Images were acquired with a Nikon TiE PFS inverted epifluorescence microscope (100 × oil objective NA 1.45 Phase Contrast) and a Hamamatsu Flash4 sCMOS camera. Images were collected with NIS elements software.

For fluorescence microscopy, cells were grown aerobically overnight to reach stationary phase in aerated minimal medium at 28 °C. To test the effect of oxygen depletion on the dynamics of the clusters, after overnight growth under shaking, cells were submitted to an argon atmosphere. The microscopic plates were prepared in a glovebox and conserved under argon atmosphere until their use in the microscope. For all samples, 2 μL of living cells are spotted onto thin pads of PBS 1% agarose. To avoid the desiccation of the thin agar pads, the agar was poured onto squared adhesive frames previously pasted onto glass slides. The slides were directly observed and photographed with a Nikon TiE PFS inverted epifluorescence microscope (100 × oil objective NA 1.45 Phase Contrast) and a Hamamatsu Flash4 sCMOS camera. Images were collected with NIS elements software. Images analyses were performed with Fiji/Image J.