Condensing Mitotic Chromosome (video) University of Massachusetts Medical School Loading video... Caption A computer simulation shows the two step process for a condensing chromosome, which happens as the cell moves from interphase to metaphase. In the first phase, chromatin loops of 80,000 to 120,000 DNA base pairs form, radiating out from a scaffold and compacting the chromosome linearly. This is followed by axial compression of the chromosome, much like a spring being compressed, and results in a neat, tightly folded package. Credit Illustration CreditsImakaev M, Fudenberg G, Naumova N, Dekker J, and Mirny L. Usage Restrictions Please credit UMMS and MIT 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.