The nucleus is dispensable for directed migration in the scratch-wound assay. (A) Percent scratch-closure for intact cells (n = 27) and cytoplasts (n = 28). (B) Percent scratch-closure for mitomycin C–pretreated intact cells (n = 27) and cytoplasts (n = 22). (C) Mean time to close half of the scratch area (t_1/2 [h]) ± 95% CI. MitoC, mitomycin C. (D) Stills from scratch assay of REF52 intact cells (top) and cytoplasts (bottom) from mitomycin C treatment. Open scratch-area outlined in yellow. Arrowheads in D and H indicate nuclei. Data in A–D are from REF52 cells. (E) Percent scratch-closure for intact cells (n = 21) and cytoplasts (n = 28). (F) Percent scratch-closure for mitomycin C–pretreated intact cells (n = 30) and cytoplasts (n = 23). (G) Mean time to close half of the scratch area (t_1/2 [h]) ± 95%CI. (H) Stills from scratch assay of HUVEC intact cells (top) and cytoplasts (bottom) from mitomycin C treatment. Data in E–H are from HUVECs. Open scratch areas are outlined in yellow; arrowheads show nuclei. Note that dead cells also stained with nuclear dye, producing high apparent background. Bars, 100 µm. All scratch-closure graphs were fit with single-phase decay regressions. All data are from at least three independent experiments. Student’s t tests were performed. ***, P < 0.001; **, P < 0.01; *, P < 0.05.