Newly polymerizing microtubules form a smaller microtubule ring in activated platelets. (A–F) Platelets with MBs at different coiling stages were triple immunostained for acetylated α-tubulin, tyrosinated α-tubulin, and total α-tubulin. Individual stainings as well as merges of 3D reconstructions of confocal z stacks are shown in the top images. The bottom images are generated from the different stainings after thresholding and skeletonizing of the MBs. For further details, see the legends of Videos 8 and 9. Bars, 2 µm.