Cu-free Click Chemistry Probe (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption These time-lapse images of a single cell over a one hour period were recorded using the copper-free click chemistry reaction of azides and DIFO. Credit Carolyn Bertozzi Usage Restrictions None 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.