Imaging the spike of the Delta variant (IMAGE) Boston Children's Hospital Caption This ribbon diagram shows the structure of the Delta variant’s spike protein before the virus fuses with its target cell. The N-terminal domain (NTD) is shown in blue and the receptor-binding domain (RBD) in cyan. Credit Bing Chen, PhD, Boston Children's Hospital Usage Restrictions Please credit as indicated. 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.