Single Yeast Cells (IMAGE) University of Groningen Caption Single yeast cells expressing Green Fluorescent Protein (GFP) and/or Red Fluorescent Protein. These particular cells were not used in the study, which was done in a similar set-up. Credit Paolo Guerra Usage Restrictions With credit 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.