DNA Dumbbells (image) University of California - Davis Caption This graphic shows DNA strung between two beads, which are held in position by laser. Credit Stephen Kowalczykowski, UC Davis Usage Restrictions May be used with acknowledgment of the source. 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.