Fig. 2. Electron micrographs of mel-Ab cells (×4,000); bars, 5 µm. (A) Electron-dense particles were observed in the cytoplasm of normal mel-Ab control cells. (B) After treatment with a picosecond 755-nm alexandrite laser, particles in the cytoplasm of mel-Ab cells disappeared or broke down into smaller parts without cell damage. (C) After treatment with a nanosecond 1,064-nm neodymium-doped yttrium aluminum laser, the particles decreased in number and size but some cell walls were destroyed, and bubble-like vacuoles developed in the cytoplasm (arrows) indicating cell damage.