MB coiling in activating platelets. (A) 3D reconstruction of confocal z stacks of three representative examples of transiently activated platelets present in PRP prepared from freshly drawn blood, fixed, and stained for acetylated tubulin (AcTub). Video 2. (B, left images) Transiently activated platelets present in PRP prepared from freshly drawn blood: either single platelets, platelets forming a small aggregate, or platelets of the same PRP, which have regained the resting state after a recovery period (120 min at RT). (right images) Platelets present in PRP prepared from buffy coats activated for 60 s with the following agonists: 6.25 µM arachidonic acid (AA), 25 nM ADP, and 0.01 U/ml thrombin (Th). Platelets are stained for α-tubulin. Video 3. (C) Time-lapse video of a microtubule tracker-stained platelet spreading on a glass surface. Transmission (left) and fluorescence (right) images are taken simultaneously every 5 s. Three time points of the activation sequence are shown: disc shape with resting MB, sphere shape with coiled MB, and spread platelet with small microtubule ring. Video 4. Time points are given in minutes and seconds. (D) Two time points of time-lapse videos of 3D reconstructions of confocal stacks of microtubule tracker-stained platelets activated with thrombin (0.017-U/ml final) and ADP (135-nM final) or treated with ATA (6.7-µM final). 3D projections are depth color coded as indicated. Video 5. (E) Two time points of a time-lapse video of 3D reconstructions of confocal stacks of microtubule tracker-stained platelets activated with ADP (270-nM final). 3D projections are depth color coded as indicated. Shown are two different view angles to observe microtubules short cutting the coiled bundle (arrow). Video 6. Bars, 2 µm.