Fig. 3.

(A) MB of a live platelet labeled with SIR-tubulin dye. Fluorescence images were segmented at the specified time after the addition of ADP, a platelet activator, to obtain the MB size $L$. (B) Simulation of a platelet at different times. A limited increase of the tension ($90\text{pN}/\mu$m) causes the MB to shorten, whereas a large increase of the tension ($220\text{pN}/\mu$m) causes the MB to buckle. (C) In simulations, the MB buckles if cell rounding is fast enough because cross-linkers cannot reorganize. This represents an elastic behavior, but at longer times, the MB rearranges, leading to a viscoelastic response.