Fig. 8. Orientation and dynamics of apoptotic microtubules. (A) Confocal immunofluorescence imaging of EB1 distribution in an apoptotic A431 cell. EB1 puncta (red) are localised to the distal tips of microtubules (green) within apoptotic spikes. The boxed areas of the merge image are shown in close-up to the right. Bar, 10 µm. (B) Kymograph derived from a time-lapse sequence of EB1-GFP dynamics in an apoptotic A431 cell spike (supplementary material Movie 7). Puncta (arrows) move towards the spike tip. (C) FRAP analysis of microtubule polymer turnover in apoptotic spikes. Frames represent images of apoptotic spikes from A431 cells stably expressing YFP-tubulin, before and after photobleaching (boxed areas). To the right, quantification of fluorescence recovery in the boxed region. Bar, 10 µm.