Force stalls MT growth and induces rapid catastrophes. Video shows a stalled MT at CT=28 µM. During barrier-contact, the MT is not observed to buckle. The video contains two subsequent growth, stalling, and catastrophe events. The first event is the same as depicted in Fig. 1 C. Images were recorded every 2 s, and the displayed frame rate is 10 frames/s. Bar, 5 µm. The tip of this short MT experiences only little upwards directed Brownian motion, and therefore, the probability that it grows over the barrier is very small. Because of this, more than 10 events can be obtained from one correctly positioned seed within half an hour, which helps in obtaining good statistics for stalled MTs.
