DNA Drag Race (IMAGE) Brown University Caption Fluorescent stained DNA molecules make their way across of fluid channel pocked with tiny pits. The pits act as 'entropic barriers.' Credit Stein lab / Brown 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.