Figure 2. Dual-color fluorescence tracing of co-cultured SU4-RFPs and MSC GFPs, followed by mono-cloning of double-positive fluorescent cells. Stable expression of RFP in SU4 cells exhibiting (A) sphere-like or (B) adherent growth. (C) Expression of GFP in MSCs from GFP-Balb/c athymic nude mice. (D) RFP+/GFP+ cells (arrows) were observed in co-cultures of SU4-RFP and MSC-GFPs. (E) RFP+/GFP+ cells were mono-cloned from the co-cultures system and (F) subcultured.