Figure 2.

Spheroids Labeled with Fluorescent Dyes

(A) Control neurosphere shows few propidium iodide+ (PI+) cells (dead, red) but many Hoechst+ cells (live, blue) in the core and that have emigrated.

(B) A toxic compound (GW406731X) causes robust PI staining. Most cells died before they could emigrate.

(C) A migration inhibitor (GSK1389063A) allows robust survival but little emigration compared with the control spheroid. The right-hand column shows merge of two fluorescent channels and bright field. Scale bar, 100 μm.