Supplementary Figure 8: Nuclear H2B fluorescence images and displacement maps under different conditions.

This cell is a representative cell in Supplementary Fig. 7. First row: brightfield images. White dashed lines are outlines of the nucleus. White arrow points to the magnetic bead. Second row: H2B fluorescence images. Note that the magnetic bead did not block the optical path because the bead was not in the optical path between the laser and the sample. Third row: H2B displacement maps when 15 Pa stress at 0.3125 Hz was applied. The pink arrow represents the magnitude and direction of the magnetic bead displacement. Bottom row: enlarged displacement maps corresponding to the white boxes above. (a) No-applied-stress (non-magnetized) confocal images. (b-e) Magnetizing in Z axis and applying a twisting field to induce 15 Pa stress at 0.3125 Hz along X-axis (the short axis of the cell); (b) image obtained with confocal microscopy. Full Width Half Maximum (FWHM) of the fluorescence image PSF is 279 nm; (c) image with 30% STED power (~21.6 mW). The FWHM is 198 nm; (d) image with 60% STED power (~43.2 mW). The FWHM is 157 nm; (e) image with 90% STED power (810 mW) (reduced to ~64.8 mW at the objective lens). The FWHM is 124 nm. Image acquisition time is 320 ms per image. Scale bars, 5 μm.