Objective: UPlanSApo 100x oil/1.40	Exposure: 250 ms
Microscope: Olympus DSU/IX81	Gain: 3
Camera: Hamamatsu ImagEM	Interval: 500 ms

The ends of microtubules are always in dynamic formation: addition or removal of tubulin proteins alters the length of the biopolymer. The rate of depolymerization is different for each end according to its polarity, and the side that grows the fastest is considered the positive end while the other, more stable terminus, is negative. The dynamic, fast-growing portion of the microtubule is composed of beta-tubulin projected out towards the membrane of the cell. The alpha-tubulins stabilize their structure toward the nucleus at the centriole located in the centrosome of the cell. Tubulin is transported around the cell by the very microtubules they modify when and where restructuring is needed. In the digital video presented above, Gray fox lung fibroblast cells (FoLu line) were transiently transfected with a fusion construct of mEGFP and human alpha-tubulin to highlight microtubules (green fluorescence) in order to visualize dynamic processes.