<i>E. coli</i> Cells (IMAGE) Proceedings of the National Academy of Sciences Caption This is a microscopy image of individual E. coli cells engineered to fluoresce bright blue upon successful integration of the LINE-1 retroelement into their genome. Credit Image courtesy of Thomas E. Kuhlman. 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.