Ferritin in a Graphene Water Balloon (IMAGE) Michigan Technological University Caption In this image generated by an electron microscope, the white dots are the protein ferritin. The dark circle in the middle is a bubble trapped within the graphene capsule enclosing the sample, which was fully hydrated during the imaging process. Credit Canhui Wang 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.