Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Thousands of Droplets for Diagnostics

25.06.2015

Researchers develop new method enabling DNA molecules to be counted in just 30 minutes

A team of scientists including PhD student Friedrich Schuler from the Laboratory of MEMS Applications at the Department of Microsystems Engineering (IMTEK) of the University of Freiburg has developed a method for dividing a DNA sample into thousands of tiny droplets.


Illustration: 3D illustration of droplet formation on a lab-on-a-chip system: Drops of water tear off from the mouths of the channels as the disk rotates. A layer of oil ensures that the drops do not combine again. Source: Hahn-Schickard

What sets it apart from previous methods is above all the fact that it is considerably easier to control and rapidly generates more than 10,000 droplets with a diameter of approximately 120 micrometers each. The entire process takes place on a rotating plastic disk the size of a DVD. The researchers presented the new method in an article in the journal Lab Chip.

Carried by centrifugal force, a watery liquid flows through channels on the rotating disk to a chamber filled with oil. At the mouth of the channel, droplets tear off – similar to a dripping faucet. A bioreaction for the detection of DNA takes place in the droplets:

They glow if they contain at least one DNA molecule, enabling the scientists to count the molecules with great precision. This is relevant for numerous clinical applications, such as cancer diagnostics, prenatal diagnostics, diagnosis of blood poisoning, or monitoring of HIV patients.

The researchers use an especially fast detection reaction known as recombinase polymerase amplification for the first time ever in the droplets, reducing the time necessary for the entire procedure from more than two hours to less than 30 minutes. Moreover, the new method enables the entire sample fluid to be distributed among the droplets, without leaving residue in channels or tubes. That saves money and reduces the amount of effort necessary to prepare sample material.

 “The disk is easy to use because all of the reactions in it run automatically, and that makes the method attractive for applications,” says Schuler. The disks are inexpensive to manufacture in an injection molding process – a precondition for diagnostic articles, which can only be used once. The researchers hope the method will soon lead to faster and improved procedures in research and hospital laboratories.

The joint research group “Lab-on-a-Chip” of Prof. Dr. Roland Zengerle, head of the Laboratory of MEMS Applications, and the research association Hahn-Schickard develops and improves analytical and diagnostic processes for fields of application in health, nutrition, demography, and the life sciences. Hahn-Schickard manufactures prototypes and pilot series of such lab-on-a-chip systems at a plant located at the Freiburg Biotech Park.

Original publication:
Centrifugal step emulsification applied for absolute quantification of nucleic acids by digital droplet RPA. Friedrich Schuler, Frank Schwemmer, Martin Trotter, Simon Wadle, Roland Zengerle, Felix von Stetten, and Nils Paust. Lab Chip, 2015,15, 2759-2766.
DOI: 10.1039/C5LC00291E


Contact:
Friedrich Schuler
Phone: +49 (0)761/203-73208
Fax: +49 (0)761/203-73299
E-Mail: Friedrich.Schuler@imtek.uni-freiburg.de

Weitere Informationen:

https://www.pr.uni-freiburg.de/pm/2015/pm.2015-06-25.91-en?set_language=en

Rudolf-Werner Dreier | University of Freiburg

More articles from Life Sciences:

nachricht Programming cells with computer-like logic
27.07.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

nachricht Identified the component that allows a lethal bacteria to spread resistance to antibiotics
27.07.2017 | Institute for Research in Biomedicine (IRB Barcelona)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Physicists Design Ultrafocused Pulses

Physicists working with researcher Oriol Romero-Isart devised a new simple scheme to theoretically generate arbitrarily short and focused electromagnetic fields. This new tool could be used for precise sensing and in microscopy.

Microwaves, heat radiation, light and X-radiation are examples for electromagnetic waves. Many applications require to focus the electromagnetic fields to...

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

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

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

Programming cells with computer-like logic

27.07.2017 | Life Sciences

Identified the component that allows a lethal bacteria to spread resistance to antibiotics

27.07.2017 | Life Sciences

Malaria Already Endemic in the Mediterranean by the Roman Period

27.07.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>