Plan apochromat 100 1.46 oil dic m27

Exponentially growing cultures were used for all microscopic analyses. The synthesis of fluorescent protein fusions was induced as indicated. To visualize nucleoids, cells were incubated with 4 µg ml⁻¹ DAPI (4′,6-diamidino-2-phenylindole) for 20 min at 28 °C under vigorous shaking (400 rpm). To acquire single snapshots, cultures were spotted onto 1% agarose pads prior to imaging at room temperature. For time-lapse analysis, cells were immobilized on pads made of 1% agarose in MB medium. The cover slides were then sealed with VLAP (1:1:1 mixture of vaseline, lanolin, and paraffin) to prevent dehydration, and microscopy was performed in an Incubator XL-4 climate chamber (PeCon, Germany) adjusted to a constant temperature of 28 °C. Images were taken with a Zeiss Axio Observer.Z1 microscope equipped with an alpha Plan-Apochromat 100×/1.46 Oil DIC M27 and a Plan-Apochromat 100×/1.40 Oil Ph3 M27 objective (Zeiss, Germany). An X-Cite 120PC metal halide light source (EXFO, Canada) and ET-DAPI, ET-CFP, ET-YFP, or ET-TexasRed filter cubes (Chroma, USA) were used for fluorescence detection. Pictures were taken with a pco.edge sCMOS camera (PCO, Germany), recorded with VisiView 2.1.4 (Visitron, Germany), and processed with MetaMorph 7.7 (Universal Imaging, USA) and Adobe Illustrator CS5 (Adobe Systems, USA).