Spinning disk confocal head

For Fig. 1D and Fig. S1A, cells on poly-D-lysine coated coverslips were placed in a magnetic holder (Chamlide CM-S22-1, LCI) and mounted on a Leica DM4000 microscope equipped with a 100x 1.4 NA oil objective, piezo stage (ASI), spinning disk confocal head (Yokogawa), EMCCD camera (Hamamatsu), 488- and 593-nm laser lines, and environmental enclosure (PeCon GmBH). Each position was imaged over a 4 micron z-depth (5 slices, 1 μm/slice) in both fluorescence channels at every timepoint, and in DIC at the first and last timepoints. For Fig. 6A, cells were grown in 35 mm glass-bottom dishes (MatTek) and imaged on a Zeiss Axiovert 200 microscope fitted with a 63x 1.4 NA objective, piezo stage (Prior), spinning disk confocal head (Perkin-Elmer), EMCCD camera (Andor), 488- and 561-nm laser lines, and temperature-controlled stage enclosure with CO₂ support (Solent Scientific). Both systems were controlled by MetaMorph (Molecular Devices). Widefield timelapse imaging was performed on a Nikon TE2000 microscope equipped with 10x, 20x, and 40x air objectives, cooled CCD camera (Hamamatsu), temperature-controlled stage enclosure with CO₂ support (Solent Scientific), and NIS Elements software (Nikon).