Collecting Yeast Samples (IMAGE) Washington University School of Medicine Caption Washington University graduate student Kim Lorenz collects yeast samples from Pennsylvania oak trees as part of a project to analyze how genes interact to produce complex traits. Credit Washington University 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.