Stem Cell Microgrooves (IMAGE) University of California - Berkeley Caption Embryonic stem cell-like colonies are shown growing on microgrooved surfaces. The staining shows cell nuclei in blue, and a pluripotent stem cell marker in green. Credit Song Li Lab Usage Restrictions All rights reserved. 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.