Looking at Colonies (IMAGE) University of Washington Caption UW civil and environmental engineering doctoral student Huan He examines how well bacteria grew on agar plates containing an antibiotic. Credit Mark Stone/University of Washington Usage Restrictions Available for reuse with appropriate credit. 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.