GBFA (IMAGE) Biophysical Society Caption This is gramicidin, a membrane-spanning protein used to monitor lipid bilayer disruption in the Gramicidin-Based Fluorescence Assay. Credit Andersen Lab, Weil Cornell Medical College Usage Restrictions This image may be used only with appropriate caption and credit. 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.