A New Way to Assess Male Fertility (IMAGE) American Chemical Society Caption More sperm travel to the right side of a central channel, which contains high concentrations of progesterone (dark green), than to the left side, which contains lower concentrations (light green). Credit Adapted from <i>Analytical Chemistry</i> <b>2019</b>, DOI: 10.1021/acs.analchem.9b05183 Usage Restrictions The image may only be used with the 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.