Now researchers at Lund University in Sweden, working together with the Swedish National Laboratory of Forensic Science, SKL, have improved a critical part of the analysis process. The first findings, published in the latest issue of the journal Biotechniques, indicate that the new method strengthens the DNA analysis so that previously negative samples yield positive and usable DNA profiles.
"The results are overwhelming. In my study I selected 32 truly difficult samples from the SKL archive, that is, with few cells, little DNA, and many so-called inhibitors, meaning lots of junk. With current methods it was impossible to get acceptable DNA profiles from any of them. But with the new method, 28 of the samples yielded more usable DNA profiles," says Johannes Hedman, an industrial doctoral candidate from SKL doing research at the Faculty of Engineering, Lund University.
Genetic information has become more and more common in forensic analyses. The analysis flow usually starts with taking a sample with a swab from a drinking glass or a blood spot, for example. The cells from the swab are then dissolved in water, and the DNA is extracted.
In forensics all over the world, much work has been done to improve the taking and handling of samples.
"The DNA analysis, on the other hand, has been something of a black box, since it is purchased as a finished product. No one has tried to improve it to be able to deal with dirty samples. But this is absolutely crucial, since the samples often have extremely small amounts of DNA. In this phase you copy certain parts of the DNA strands and then obtain a DNA profile that is unique to each person.
In the copying step, I have optimized the chemical environment and replaced a key enzyme, a so-called DNA polymerase. This yields a clearer genetic footprint, a DNA profile, to work with," explains Johannes Hedman. He has also devised a new mathematical model that makes it easy to interpret the DNA analysis.
If the copying phase is improved, stronger DNA evidence can be shown from crime scenes that today provide only partial or entirely blank DNA profiles. In other words, the chances are greater that a person can be found and linked to a particular crime.The reason Johannes Hedman wound up at Lund is the fact that Peter Rådström, a professor of microbiological engineering, has been working
since the late 1980s to improve DNA-based infection diagnostics and microbiological analyses for food. SKL was eager to find out whether these research findings could be applied to improving forensic DNA analysis.
"This collaboration opens new vistas for both SKL and Lund University, and we hope to be able to continue to work together with Peter Rådström's team. We have truly seen cross-fertilization," says Birgitta Rasmusson, research director at SKL.Read the article here:
Kristina Lindgärde | idw
Don't Give the Slightest Chance to Toxic Elements in Medicinal Products
23.03.2018 | Physikalisch-Technische Bundesanstalt (PTB)
North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich
Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.
The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
23.03.2018 | Event News
19.03.2018 | Event News
16.03.2018 | Event News
23.03.2018 | Materials Sciences
23.03.2018 | Agricultural and Forestry Science
23.03.2018 | Physics and Astronomy