Figure 4. Imaging of apoptosis of the LECs. The round apoptosis area could be readily distinguished after 30 min (A–C). Apoptotic cells showed green fluorescence (YO-PRO^®-1; D), and dead cells showed primarily red fluorescence (PI; E, J). Blue-fluorescent Hoechst 33342 stained the condensed chromatin of apoptotic cells and the normal chromatin of live cells (F, K). C: A merging of D, E, and F. B: A merging of A and C. After 30 min, the cell borders and small, rounded humps were clearly observed (G). After five h, the nuclei of the apoptotic cells moved aside, and round caves were left in the original sites (H). After 20 h, the nuclei were invisible under an optical microscope, and there were only round caves in the irradiation area (I). Fluorescent staining showed that all of the cells were dead, and the nuclei lay adjacent to the round caves (J–L). L: A merging of I, J, and K. High-magnification images of the apoptotic cells are shown in the rectangles. Scale bars: A–L=50 μm.