TIP activity of CLIP-170(H2)–GFP (a carboxyl truncation of the plus end microtubule tracking protein CLIP-170) in the presence of EB1 protein (a plus end microtubule tracking protein). The movie shows pseudocolored overlaid images of rhodamine-labeled microtubules (red) and GFP-tagged CLIP-170(H2) protein (green). In the presence of unlabeled EB1, CLIP-170(H2)–GFP specifically localizes to growing microtubule plus-ends and is lost during microtubule shortening phases. (Scale bar, 2 micron.) Microtubule dynamics were visualized at 22 °C using a TIRF microscope fitted on an inverted microscope (Nikon TE-2000U). Images were captured with a backilluminated electron-multiplying CCD camera (Cascade-512B, Photometrics) using time-lapse capture at 2-sec intervals for 2-color microscopy. Movie corresponds to Video S3 from Proc Natl Acad Sci U S A. 2009 Jan 13;106(2):492-7. Epub 2009 Jan 6.