Bacteria Built with Arsenic (IMAGE) DOE/SLAC National Accelerator Laboratory Caption Scientists have found the first known living organism that incorporates arsenic into the working parts of its cells. What's more, the arsenic replaces phosphorus, an element long thought essential for life. Staff scientist Sam Webb led the research undertaken at the Stanford Synchrotron Radiation Lightsource located at SLAC National Accelerator Laboratory. The results were published online today in Science Express. Credit Brad Plummer/SLAC Usage Restrictions Please credit where possible. 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.