Fig. 3. CD34 and Sca-1-positive cells in Matrigel vessels. Sections from 5 day (A-H) and 9 day (I-L) Matrigel plugs were stained for DAPI (blue), NG2 (magenta), CD34 (red), Sca-1 (red) and CD31 (green). Prior to the appearance of CD31⁺ endothelial cells, many cells in the vessel-like networks co-express NG2 and the markers CD34 and Sca-1. In older plugs, CD34 is co-localized with CD31 on endothelial cells. A CD31^- CD34^- pericyte is marked with an arrowhead. All panels are z-stacks of confocal images. Scale bars: 40 µm.