To deduce the double helix structure of deoxribonucleic acid 59 years ago, scientists James Watson, Francis Crick, Maurice Wilkins, and Rosalind Franklin bounced X-rays off of the DNA and used that data to reconstruct its shape. But now, physicist Enzo Di Fabrizio, a professor at the Magna Graecia University in Catazaro, Italy, has snapped the very first direct picture of the structure of DNA.
Credit: Enzo Di Fabrizio
To get these incredible shots, Di Fabrizio and his team "built a nanoscopic landscape of extremely water-repellant silicon pillars," according to Eli MacKinnon at LiveScience, and "added a solution that contained strands of DNA into this scene." The water evaporated and left behind DNA that stretched between the pillars; Di Fabrizio then shone beams of electrons through the holes in the silicon bed and snapped images of the illuminated molecules using an electron microscope.
"Di Fabrizio's images actually show a thread of several interwoven DNA molecules, as opposed to just two coupled strands," MacKinnon writes. "This is because the energy of the electrons used would be enough to destroy an isolated double helix, or a single strand from a double helix." But by using more sensitive equipment and lower energy electrons, Di Fabrizio believes he will eventually be able to photograph an individual double helix; in the meantime, scientists will be able to use Di Fabrizio's method to see how DNA interacts with the other ingredients of life, like ribonucleic acid, or RNA.