Dynamic nature of TNT formation between BCP-ALL cells and MSCs. (A-C) Time-lapse confocal images (3D image stacks) showing TNT formation (white arrowhead) between NALM6 cells (DiI, yellow) and primary MSCs at multiple time points. White arrow indicates transfer of dye to recipient cell. Time indicated in the right lower corner is the duration from start of the experiment. Orange Hot look-up table (LUT) and transmission overlays were used to illustrate dye transfer toward MSCs. Scale bars represent 10 µm. (A,C) Depicted images are closeups of the upper left corner of supplemental Video 3. (B) Depicted images are closeups of supplemental Video 4A. Data are representative of 3 independent experiments (see also supplemental Figure 5 and supplemental Videos 3 and 4A-B).