The nucleus is dispensable for migration in 1D, but not 3D. (A) Illustration of collagen matrix (left) for measuring 2D and 3D cell migration. Reflectance images (right) from 1.9 mg/ml self-assembled collagen polymerized to form LR or HR matrices, respectively. Bar, 50 µm. Image stack depth is 100 µm. (B) Mean 2D cell velocity ± SEM for REF52 cells on top of LR or HR matrices. Intact LR, n = 184; cytoplast LR, n = 169, intact HR, n = 62; cytoplast HR, n = 52. (C) Mean 3D REF52 cell velocity ± SEM for cells embedded in LR or HR matrices. Intact LR, n = 136; cytoplast LR, n = 111, intact HR, n = 50; cytoplast HR, n = 54. (D) Images of intact REF52 cells and cytoplasts in 3D LR collagen. Bar, 50 µm. Image stack depth is 70 µm. (E) Stills (left) of an intact cell (top) and cytoplasts (bottom) at 0 h (yellow outline) and 3.3 h (red outline). Graph (right) showing accumulated distance ± SEM from continuous 8 h of 3D migration for intact REF52 cells (n = 71) and cytoplasts (n = 64). (F) Graph (left) showing mean 3D cell velocity ± SEM for HUVECs embedded in LR matrix. Intact, n = 57; cytoplast, n = 64. Graph (right) showing accumulated distance ± SEM from continuous 8 h of 3D migration for intact cells (n = 35) and cytoplasts (n = 41). (G) Images of REF52 cells on 5-µm lines (left) and mean cell velocity ± SEM for 1D migration (right). Intact cells, n = 110; cytoplasts, n = 151. (H) Images of HUVECs on 5-µm lines (left) and mean cell velocity ± SEM for 1D migration (right). Intact cells, n = 96; cytoplasts, n = 108. Bars: (E, G, and H) 20 µm. All data are from at least three independent experiments. Student’s t tests were performed. ***, P < 0.001; **, P < 0.01; *, P < 0.05.