December 2, 2012
(Credit: Francesco Gentile et al./Nano Letters)
The technique will let researchers see how proteins, RNA and other biomolecules interact with DNA.
The structure of DNA was originally discovered using X-ray crystallography, requiring complex mathematics to reconstruct the crystal structure from the observed patterns.
The new images are a direct picture of the DNA strands, seen with electrons rather than X-ray photons. The trick used by Enzo di Fabrizio at the University of Genoa, Italy, and his team was to snag DNA threads out of a dilute solution and lay them on a bed of nanoscopic silicon pillars. The results reveal the corkscrew thread of the DNA double helix, clearly visible.
Using more sensitive detectors that can respond to lower-energy electrons should soon allow the team to see individual double helices, and even unwound single strands of DNA.