Sperm (IMAGE) Universitat Rovira i Virgili Caption Human sperm stained for semen quality testing in the clinical laboratory. Credit ©Bobjgalindo Usage Restrictions This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International, 3.0 Unported, 2.5 Generic, 2.0 Generic and 1.0 Generic license. 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.