Single-cell Living Laser (IMAGE) Massachusetts General Hospital Caption This is a microscope image of a single-cell living laser in action. The irregular internal structure of the green-fluorescent-protein-expressing cell causes the apparently random pattern of laser light emission. Credit <I>Nature Photonics</I> and to Malte Gather, Mass. General Hospital Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.