How LEDs Power a One-Step Hydrogen Isotope Exchange (image) Princeton University Share Print E-Mail Caption From left: Gleevec, an anti-cancer drug, is submerged in heavy water (T2O) and bathed in blue LED light to replace hydrogen atoms with tritium atoms (green circles) in a one-step direct hydrogen isotope exchange (HIE). Clinicians can trace radioactive compounds in the body using sophisticated imaging technologies for research and diagnostic purposes. Credit Yong Yao Loh, Kazunori Nagao, and David MacMillan/Princeton University Usage Restrictions Editorial use only Share Print E-Mail 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.