Fig. 5. Percentage of TUNEL-fluorescent apoptotic sea urchin embryos observed by confocal laser scanning microscopy. 8-blastomere embryos were incubated in 5 µg ml^-1 DD or 5 µg ml^-1 decanal for 30, 60, 90 and 120 min, and then stained with TUNEL. See Materials and methods for details. Values (means ± S.D.; N=200) are the results of three different experiments.