Microtubule polarity and (+) end vs. (-) end tracking
Microtubules have an intrinsic polarity with a slow growing (-) and a faster growing (+) end. Usually, (+) end dynamics are reported. The user can use time slider to navigate through time frames to identify the plus ends only and mark them for tracking. The default setting is that all recognized ends will be tracked over the complete time duration of the movie. Clicking “Confirm dynamic seeds” will show which seeds are going to be tracked. In the final track files the plus and minus ends will be determined by the program by comparing the growth velocity of the two ends it is tracking and plus end would be the one which has on an average a higher growth velocity than the other end.
If the user deselects certain ends that end would be labelled as zero end, same is true for the ends which are not recognized by the program but are user selected.