Gap junctions between BCCs and BM stroma. (A) T47D or MCF7 was cultured alone or as cocultures. Cultures were colabeled with CX-43 and the F-actin label, phalloidin. Figure shows representative labeling at magnification × 100. Cells shown in the top row (visible light) are presented as merged staining with anti–CX-43 and phalloidin on the bottom row. Arrows show CX-43 between BM stroma and BCCs. (B) Cocultures were established with the following modification: the BCCs were labeled with Vybrant CFDA SE cell tracer (green) and then added to BM stroma. After 24 hours, the cells were labeled with anti–CX-43 (red). Images were visualized, acquired, and processed as in Figure 3C, except that a 50 ×/0.9 NA objective was used.