Figure 4: Qualitative comparison of CFP-fluorescent B3 cells under control and differentiating culture conditions. Clone B3 cells were cultured under routine (control) (a)–(c) or differentiating (d)–(f); 20 ng/ml epidermal growth factor, 0.5 ng/ml transforming growth factor b, 1% serum) culture conditions for 9 days. Shown are phases (a), (d), fluorescent (b), (e), and merged (c), (f) images. Arrows indicate morphologically differentiated cells. Scale bar is equivalent to 100 μm.