Plan apochromat 100 1.45 na

C. crescentus cells were grown up to exponential phase (OD_660nm < 0.3) and spotted on 0.3% agarose pads containing M2G medium, unless specified otherwise. Microscopy was performed on an Eclipse 80i microscope (Nikon, Tokyo, Japan) equipped with a phase-contrast objective Plan Apochromat 100×/1.40 NA (Nikon, Tokyo, Japan), an Orca-II-ER (Hamamatsu Photonics, Hamamatsu City, Japan) and an Andor iXon DU-897E camera (Andor Technology Ltd., Belfast, UK) with 2× optivar. Images were acquired every 2.5 min using MetaMorph software (Molecular Devices, Sunnyvale, CA, USA). For still images of E. coli strains, cells were grown at 30°C up to exponential phase (OD_600nm<0.3) and spotted on 1% agarose pads. For microfluidic experiments, E. coli cells were loaded and grown for at least 5 generations in the microfluidic device prior to imaging. Microscopy was performed on an Eclipse Ti-E microscope (Nikon, Tokyo, Japan) equipped with Perfect Focus System (Nikon, Tokyo, Japan) and an Orca-R2 camera (Hamamatsu Photonics, Hamamatsu City, Japan) and a phase-contrast objective Plan Apochromat 100×/1.45 NA (Nikon, Tokyo, Japan). Time-lapse images were acquired every 5 sec using NIS-Element Ar software (Nikon Instruments INC., Melville, NY USA).