Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Thousands of Droplets for Diagnostics


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

Friedrich Schuler
Phone: +49 (0)761/203-73208
Fax: +49 (0)761/203-73299

Weitere Informationen:

Rudolf-Werner Dreier | University of Freiburg

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>