DNA imaged with electron microscope for the first time

December 2, 2012

(Credit: Francesco Gentile et al./Nano Letters)

An electron microscope has imaged threads of DNA directly or the first time, New Scientist reports.

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.