Extrachromosomal DNA (IMAGE) University of California - San Diego Caption In this scanning electron micrograph of inside the nucleus of a cancer cell, chromosomes are indicated by blue arrows and circular extra-chromosomal DNA are indicated by orange arrows. Credit Image courtesy of Paul Mischel, UC San Diego. Usage Restrictions Please credit Paul Mischel, UC San Diego. 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.