Figure 1. Isolation and characterization of side population (SP) cells from the mouse lens epithelium. Fluorescence-activated cell sorting (FACS) analysis of mouse lens epithelial cells stained with Hoechst 33342 alone (A) or in the presence of verapamil (B). The P1 region shows the gated region identified SP cells. The P2 region is designated as non-SP cells. SP cells (C) and non-SP cells (D) were observed by phase contrast microscopy. The scale bar represents 10 µm. (E) Forward scatter characteristics (FSC) of SP cells (solid area) and non-SP cells (open area) were analyzed by FACS.