In vivo Performance (IMAGE) RIKEN Caption Bioluminescence images of mice intravenously injected with 103 HeLa cells expressing Fluc (left) or Akaluc (right). Substrate administration was performed intraperitoneally. Images were acquired using a cooled CCD camera (1-min exposure time). The AkaLumine-HCl/Akaluc signals were statistically compared to D luciferin/Fluc signals. Data are presented as mean ± SEM of n = 3 mice. Credit RIKEN Usage Restrictions credit RIKEN 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.