SOIL 2 (IMAGE) Rice University Caption The two-stage biosensors developed by Rice University graduate student Hsiao-Ying (Shelly) Cheng are programmed to release puffs of gas to report on their presence and activity levels in genetically engineered bacteria like E. coli. They mimic the features of fluorescent sensors scientists use to monitor biological activity, but in opaque environments like soil. Credit Jeff Fitlow/Rice University 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.