Figure 3: The 3D confocal time-lapse microscopy of cell division.

(a) HeLa cells stained with 200 nM SiR–Hoechst were imaged over 3.4 h with a time lapse of 4.8 min. Images show maximum intensity projections of five Z-sections. To quantify control cells without staining in the far-red channel, a stably expressed histone 2B (H2B)-mCherry was used as a reference chromatin marker. Scale bar, 10 μm. (b) Mitotic duration was measured as the time from prometaphase onset until anaphase onset, based on visual inspection of the image data. (c) Chromosome missegregation was quantified as the number of anaphase events with lagging or bridged chromosomes divided by the total number of anaphase events, based on visual inspection. SiR–Hoechst was present in culture media throughout the entire imaging duration. Bars show mean±s.d. (n=3 independent biological replicates). DMSO, dimethylsulfoxide.