Cytoskeleton - microtubules Microtubules function as a rail
network, transporting vesicles to different locations within the
cell. They start out from the microtubule organizing centre
(MTOC) at the centrosome and stretch out to the edges of the
cell. At high enough concentrations of the tubuli subunits, the
microtubules will spontaneously self assemble, and when the
concentration dips they will disassemble. This process of
dynamic instability is much faster at the free ends of the
tubules, thus referred to as the plus ends, whereas the slowly
changing minus ends are joined together at the MTOC. During
mitosis the microtubule network will completely disassemble and
instead form what will become the mitotic spindle, responsible
for separating the duplicated chromosomes into the two daughter
cells. Immunofluorescent staining of microtubules shows thin
strands that stretch throughout the whole cell. It is almost
always possible to detect the center from which they all
originate, the centrosome, even though it ne