Optimized antibody, C10-S66K (IMAGE) Scripps Research Institute Caption A crystal structure of the optimized antibody, C10-S66K. The binding pocket of C10‐S66K with fentanyl and carfentanil is displayed as a grey surface with fentanyl and carfentanil shown as green and yellow sticks, respectively. Credit Scripps Research Usage Restrictions With related coverage and credit License Original 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.