Can DNA easily get bent out of shape?
Even when biophysicist Paul Wiggins pursues his favorite sport, rock climbing, he doesn't leave his work behind. While struggling to untangle ropes—"one of the most frustrating aspects of climbing," he says—Wiggins envisions great lengths of DNA tangled inside cells. The mechanical properties, particularly the flexibility, of that biomolecule fascinate him.
In cells, random thermal motion makes DNA and other long biomolecules wriggle. Experimenters have observed that the distance between bends in DNA tends to be around 50 nanometers. The stiffness of stretches short