Model acupuncture point: Bone marrow-derived stromal stem cells are moved by a weak electromagnetic field

Figure 2 The scheme for photographic fields of the bottom of the culture dish. The numbers mark the concentric regions: The central region (1); the area near the central region (2); the area near the fringe region (3); the fringe region (4). The dotted lines divide the bottom into four sectors. Each sector comprises four photographic fields; thus, overall, there are 16 photographed fields for each culture dish.