Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New miniaturised chip dramatically reduces time taken for DNA analysis

04.04.2005


The portable device will speed up performing paternity tests, identifying bacterial infections and detecting genetically modified organisms (GMOs)



A team of researchers at the Universitat Autònoma de Barcelona has developed new miniature sensors for analysing DNA. The sensors have the same size and thickness as a fingernail and reduce the time needed to identify DNA chains to several minutes or a few hours, depending on each chain. These sensors can be applied to many different tasks, ranging from paternity tests and identifying people to detecting genetically modified food, identifying bacterial strains in foodborne illnesses and testing genetic toxicity in new drugs. Once mass production of the sensors begins, their cost and availability will be similar to that of pregnancy test kits found in pharmacies.

The researchers Salvador Alegret, Manuel del Valle and Maria Isabel Pividori, all of whom are members of the Sensors and Biosensors Group at the UAB’s Department of Chemistry, developed the new sensors based on their experience in research with electrochemical sensors. These can identify a substance by chemically interacting with it and converting this interaction into an electrical current that they measure.


To detect DNA, the new miniaturised electrochemical genosensors have a probe containing DNA fragments that complement the DNA they aim to detect. For example, to detect Salmonella in a sample of mayonnaise, the probe has fragments of the type of DNA that complements that found in a group of genes that identify the bacteria. When the probe is submerged into the mayonnaise, some of the DNA fragments from the bacterial cells join the complementing fragments from the probe, creating a measurable electrical current. The sensor converts this current into a signal that can be seen by the person controlling the tests, making him aware there are bacteria. Also, because the sensors are very small and easy to manipulate, it is possible to assemble a set of sensors that can collect data simultaneously and deduce information about the bacteria such as which strain caused the foodborne illness.

This type of analysis already takes place in laboratories, but until now the experimental measures needed were not suitable for in situ analysis. By using the new sensors developed by UAB scientists, the time taken to identify the source of infection for Legionella would decrease from two days, as is currently the case using organic production techniques, to just thirty minutes. In trials developed with the support of the UAB’s Department of Genetics and Microbiology, the new sensors have enabled Salmonella to be identified in four and a half hours, compared to three to five days using the traditional microbiological methods. This method for identifying bacteria could also be used to detect other infectious agents such as Campylobacter and Listeria, and the sensor could easily be adapted for use in medicine, environmental monitoring and the industrial sector.

Other important applications for DNA sensors include: detecting genetically modified organisms in food, either in basic ingredients or in prepared food; identifying people, either to establish blood relations or to find criminal evidence; and testing the toxicity of different drugs to establish what damage they may cause to the DNA molecule of disease-causing microorganisms and of cells in patients.

"The next step is to mass-produce the sensors", states Salvador Alegret, the director of research. "Mass production will allow costs to be reduced and the product to become as widely available as pregnancy test kits we can buy at the local pharmacy".

Electrochemical genosensors vs DNA chips

Identifying DNA chains has become increasingly important in biochemistry, medicine and biotechnology. But traditional DNA-analysis techniques are becoming outdated as demand increases for more genetic information to be found in less time and at a lower cost. An important step forward in this direction was the creation of DNA chips, in which the UAB played a leading role in Catalonia. Hundreds, or even thousands, of genetic tests can be performed simultaneously with these chips, which are now a vital part of any large-scale project, such as unlocking the genetic code of an organism. DNA chips are limited to a certain extent because of some very specific analytical problems, such as establishing the source of microbial contamination quickly and efficiently. The new miniaturised electrochemical genosensors meet the current need for DNA to be analysed at a low cost with easy-to-use devices that do not need to be supervised by highly trained scientists.

Octavi López Coronado | EurekAlert!
Further information:
http://www.uab.es

More articles from Health and Medicine:

nachricht Cholesterol-lowering drugs may fight infectious disease
22.08.2017 | Duke University

nachricht Once invincible superbug squashed by 'superteam' of antibiotics
22.08.2017 | University at Buffalo

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>