Observing HCN Channels (image) Rockefeller University Press Caption These schematic drawings show how researchers applied laser pulses to HCN channels tagged with a fluorescent photosensitizer to observe the effects on these channels of singlet oxygen, a highly reactive form of oxygen that plays a role in a range of biological processes including photosynthesis and skin cancer/aging. Credit Gao et al., 2014 Usage Restrictions Reporters may freely use these materials in news coverage, with the appropriate credit information. 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.