AS IF untangling the meaning of DNA weren’t complicated enough, scientists are now tying the molecules themselves in knots.
Robert Bao and colleagues at the California Institute of Technology in Pasadena hope that knots tied in the laboratory will unravel the secret of what happens in cells when DNA scrunched up in the nucleus becomes tangled.
To knot the DNA, the team attached polystyrene beads to the ends of individual molecules. By manipulating the beads with optical tweezers, which grip with a carefully focused light beam, the team made simple knots, figures of eight, and some knots with multiple twists…
