Blood Outgrowth Endothelial Cells (IMAGE) Imperial College London Caption The new test uses endothelial cells grown from stem cells in the blood. This image shows these cells stained with fluorescent markers. Credit Imperial College London 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.