Fig. 4.

Experimental reporter assay. (A) Depiction of the experimental reporter assay: green reporter tubulin incorporates at microtubule plus ends, and at gaps and defects in the lattice through a repair process. The amount of lattice-incorporated green reporter tubulin is expected to be higher for more disrupted microtubule structures (right, bottom), and lower for more intact lattice structure (right, top), but green extensions at microtubule plus-ends will be observed in both cases. (B) Depiction of TIRF imaging process. (C) Example image, showing a microtubule with a green tubulin extension at the plus end (right), with a gap that has been filled by green reporter tubulin (left, white arrow).