Math Trek Math

Detangling DNA

DNA can form some very nasty knots — but not just any knots

By Julie Rehmeyer

- More than 2 years ago

Deep inside our cells, the DNA that encodes the mysteries of our individuality twines into tidy little spiral staircases neatly side by side — or so we might imagine.

A KNOTTY PROBLEM Bacterial DNA is joined at the two ends, forming a circle. This electron microscope image shows circular DNA that has formed the simplest kind of knot, known as the trefoil.