Detecting Viruses (IMAGE) Iowa State University Caption Edward Yeung uses laser beams to light up tags that indicate molecules of human papillomavirus are present in a cell. Credit Jim Heemstra 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.