“The technique is quicker, easier and cheaper than existing methods. Therefore we hope that it can be used in hospitals in the future. Mapping a person’s genome, or genetic make-up, is currently an expensive and complicated process”, explains Jonas Tegenfeldt, researcher in Solid State Physics at Lund University and one of the senior authors of the article.
According to the researchers, the technique could be used to find out more easily whether someone is carrying a genetic predisposition to certain diseases.
The hope is that it could be used to diagnose and characterise diseases that are caused by significant changes and mutations in the genetic make-up, known as structural variations, that are associated with, for example, cancer, autism and several hereditary diseases. In addition, the method could be of use in criminal investigations, because it might speed up identification of evidence.
The technique, which has recently been patented, utilises the fact that different parts of the DNA molecule melt at different temperatures. A central component of the DNA molecule is the nucleobase pairs. These are found in two pair varieties; AT, which stands for adenine and thymine, and GC, which stands for guanine and cytosine. The GC pair is more firmly bound and requires a higher temperature to melt.
By first stretching out the tightly twisted DNA molecule in a nanochannel and then heating it up so that only the AT pair melt, it is possible to obtain a ‘barcode’ of the person’s 46 chromosomes. In order to make certain parts darker than others, the DNA molecule must be stained. The parts that melt – the AT parts – emit less fluorescence and become dark fields in the barcode.
The image produced shows the rough composition of the DNA molecule, and thus that of the chromosome. Such ‘barcodes’ are nothing new, but this approach to creating the barcodes is completely new. With this method, the DNA analysis process becomes significantly shorter, from 24 hours to around one or two hours.
“The barcode technique could be a simple way to identify what types of virus and bacteria we are dealing with. We can also find out whether something has gone wrong in the human genome, because it is possible to see if any part of the chromosome has moved for any reason. This is what happens in certain diseases”, explains Jonas Tegenfeldt, adding that beyond all the applications an important motivation for the research is still ‘just’ basic scientific curiosity.
A further advantage of this barcode technique over other techniques is that only one DNA molecule is required. The fact that the DNA does not have to be amplified also means that it is easy to compare a number of cells and thereby discover any differences between them.
The method provides a rough image of the genome, but compared to other similar methods, such as chromosome banding, the image is still a thousand times sharper. The fact that the measurements must be performed on each molecule individually could also pose a limitation; it is not easy to obtain an average from a large number of molecules.
For more information, please contact Jonas Tegenfeldt, researcher at the Division of Solid State Physics at the Faculty of Engineering, Lund University, +46 (0)46 222 8063 or firstname.lastname@example.org.
Ingemar Björklund | idw
The birth of a new protein
20.10.2017 | University of Arizona
Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research