E. coli Antibiotic Plate (image) University of Washington Caption This is a plate where each small well holds a population of E. coli being subjected to an antibiotic. Wells that are cloudy have fully grown bacterial populations of millions of cells. Wells that are more clear correspond to populations that have gone extinct. Credit S. Hammarlund/U of Washington Usage Restrictions Credit required 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.