DNA sequencing: slower, but more accurate
An improved DNA sequencing technology is presentedDmitry Safin, "Kompyulenta"
In recent years, human DNA sequencing has become noticeably more accessible; as you know, specialists of the American system of the National Institutes of Health have set researchers the task of reducing the cost of the procedure to thousands of dollars as soon as possible.
Several scientific groups are working on the creation of effective sequencing methods at once.
Recently, physicists from Brown University (USA) presented their original development. Scientists took as a basis the well-known method of decoding the nucleotide sequence, which involves reading information when passing DNA molecules through miniature holes in the material, and eliminated its main drawback, which was that the rate of passage of base pairs through the hole was too high (as a result, the decoding accuracy decreased).
In order to slow down the process, the researchers "attached" a DNA molecule to an iron oxide particle, taking advantage of the property of biotin to form a strong bond with streptavidin. Manipulating the parameters of an electric field of sufficiently high intensity, physicists directed the resulting bundle towards the hole in the membrane; the molecule freely passed through, and a particle with a diameter of 2.8 microns "stuck" on the opposite side (the diameter of the pore is only about 10 nm). The scientists then used magnets to force the particle to move in the opposite direction, thus controlling the decoding speed.
According to the authors, they managed to reduce the average rate of passage of base pairs through the hole by about two thousand times. "It is possible, however, to slow down even further, up to a complete stop," says Xinsheng Sean Ling, one of the study participants. "After all, the speed of movement is set by a simple ratio of the parameters of the electric and magnetic fields." Scientists also note that their technique allows for simultaneous processing of several sections of DNA.
In the near future, the researchers plan to test a new technology using bacterial DNA.
The full version of the scientists' report is being prepared for publication in the journal Nanotechnology.
Prepared based on the materials of EurekAlert!.
Portal "Eternal youth" www.vechnayamolodost.ru17.04.2009