Enzo Di Fabrizio
DNA's double-helix structure is on display
for the first time in this electron microscope photograph of a small
bundle of DNA strands.
By Eli MacKinnon
Fifty-nine years after James Watson and Francis Crick deduced
the double-helix structure of DNA, a scientist has captured the first
direct photograph of the twisted ladder that props up life.
Previously, scientists had only seen DNA's structure indirectly. The double-corkscrew form was first discovered using a technique called X-ray crystallography, in which a material's shape is reconstructed based on how X-rays bounce after they collide with it.
Enzo Di Fabrizio
A bundle of DNA is supported by two silicon pillars.
But Di Fabrizio and his colleagues developed a plan to bring DNA out of hiding. They built a nanoscopic landscape of extremely water-repellant silicon pillars. When they added a solution that contained strands of DNA into this scene, the water quickly evaporated and left behind cords of bare DNA that stretched like tightropes between the tiny mesas.
They then shone beams of electrons through holes in the silicon bed, and captured high-resolution images of the illuminated molecules.
Di Fabrizio's images actually show a thread of several interwoven DNA molecules, as opposed to just two coupled strands. 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 with the use of more sensitive equipment and lower energy electrons, Di Fabrizio thinks that snapshots of individual double helices will soon be possible, New Scientist reports.
Molecules of DNA, or deoxyribonucleic acid, store the genetic instructions that govern all living organisms' growth and function.
Di Fabrizio's innovation will allow scientists to vividly observe interactions between DNA and some of life's other essential ingredients, such as RNA
(ribonucleic acid ). The results of Di Fabrizio's work were published in the journal NanoLetters.
No comments:
Post a Comment