SxIP-iLID constructs track MT plus ends and do not dramatically perturb MT comet velocities. (A) Schematic of EGFP-labeled SxIP-iLID constructs. (B) Cartoon diagraming EGFP-SKIP-LZ-iLID at a MT plus end. (C) Representative images of EGFP-SxIP-iLID constructs in S2 cells. Bars: 5 µm; (inset) 1 µm. Kymographs below each image show a representative EGFP-SxIP-iLID MT plus end comet. See accompanying Video 1. (D) The ratio of mean EGFP-SxIP-iLID construct intensity on a MT plus end per area relative to the mean intensity per area in an adjacent cytoplasmic region. (E) The number of EGFP positive comets per μm². (F) SxIP-iLID constructs show some variation in EGFP comet velocities; however, mean comet velocities of the SKIP-LZ-iLID construct and the EB1-GFP control are not significantly different. Error bars indicate the SD. Numbers in parentheses indicate (number of experiments, total number of cells quantified). P-values were determined by two-way unpaired Student’s t test. *, P < 0.05; **, P < 0.005; ****, P < 0.0001.