Germ-Free Mice (IMAGE) University of Wisconsin-Madison Caption Nacho Vivas, lab manager at the Rey Lab, checks on a group of germ-free mice inside a sterile environment. Credit Bryce Richter/UW-Madison Usage Restrictions Credit Bryce Richter/UW-Madison 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.