Adding a Centromere (IMAGE) University of Pennsylvania School of Medicine Caption Human artificial chromosome (HAC, green) with two sister centromeres (red), similar to that of the natural host chromosomes (blue). Credit Glennis Logsden, Penn Medicine, <em>Cell</em> 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.