Movie S1.

Time-lapse fluorescence microscopy movie showing an example of an HCT116 cell expressing GFP-tagged EB3 and used to measure microtubule plus-end assembly rates in a bipolar metaphase spindle. Images with four z-stacks were recorded every 2 s; deconvolved and maximal projections are shown. The movie has a speed of eight frames/s. (Scale bar, 10 µm.)