Measuring Isotope Ratios (IMAGE) Arizona State University Caption Researchers Amrita Rhoads and Gwyneth Gordon measure isotope ratios in a hair sample to estimate what participants typically ate. Credit ASU 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.