Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New biochip technology uses tiny whirlpools to corral microbes

09.01.2013
Researchers have demonstrated a new technology that combines a laser and electric fields to create tiny centrifuge-like whirlpools to separate particles and microbes by size, a potential lab-on-a-chip system for medicine and research.
The theory behind the technology, called rapid electrokinetic patterning - or REP - has been described in technical papers published between 2008 and 2011. Now the researchers have used the method for the first time to collect microscopic bacteria and fungi, said Steven T. Wereley, a Purdue University professor of mechanical engineering.

The technology could bring innovative sensors and analytical devices for lab-on-a-chip applications, or miniature instruments that perform measurements normally requiring large laboratory equipment. REP is a potential new tool for applications including medical diagnostics; testing food, water and contaminated soil; isolating DNA for gene sequencing; crime-scene forensics; and pharmaceutical manufacturing.

"The new results demonstrate that REP can be used to sort biological particles but also that the technique is a powerful tool for development of a high-performance on-chip bioassay system," Wereley said.

A research paper about the technology was featured on the cover of the Dec. 7 issue of Lab on a Chip magazine, and the work is highlighted as a news item in the Jan. 13 issue of Nature Photonics, posted online Dec. 27. Mechanical engineering doctoral student Jae-Sung Kwon, working extensively with Sandeep Ravindranath, a doctoral student in agricultural and biological engineering, was lead author of the Lab on a Chip paper.

The technology works by using a highly focused infrared laser to heat a fluid in a microchannel containing particles or bacteria. An electric field is applied, combining with the laser's heating action to circulate the fluid in a "microfluidic vortex," whirling mini-maelstroms one-tenth the width of a human hair that work like a centrifuge to isolate specific types of particles based on size.
Particles of different sizes can be isolated by changing the electrical frequency, and the vortex moves wherever the laser is pointed, representing a method for positioning specific types of particles for detection and analysis.

The Lab on a Chip paper was written by Kwon; Ravindranath; Aloke Kumar, a researcher at the Oak Ridge National Laboratory; Joseph Irudayaraj, a Purdue professor of agricultural and biological engineering and deputy director of the Bindley Bioscience Center; and Wereley.

Much of the research has been based at the Birck Nanotechnology Center at Purdue's Discovery Park, in collaboration with Irudayaraj's group in the Bindley Bioscience Center.

The researchers used REP to collect three types of microorganisms: a bacterium called Shewanella oneidensis MR-1; Saccharomyces cerevisiae, a single-cell spherical fungus; and Staphylococcus aureus, a spherical bacterium. The new findings demonstrate the tool's ability to perform size-based separation of microorganisms, Wereley said.

"By properly choosing the electrical frequency we can separate blood components, such as platelets," Wereley said. "Say you want to collect Shewanella bacteria, so you use a certain electrical frequency and collect them. Then the next day you want to collect platelets from blood. That's going to be a different frequency. We foresee the ability to dynamically select what you will collect, which you could not do that with conventional tools."

The overall research field is called "optoelectrical microfluidics." More research is needed before the technology is ready for commercialization.

"It won't be on the market in a year," Wereley said. "We are still in the research end of this. We are sort of at the stage of looking for the killer app for this technology."

REP may be used as a tool for nanomanufacturing because it shows promise for the assembly of suspended particles, called colloids. The ability to construct objects with colloids makes it possible to create structures with particular mechanical and thermal characteristics to manufacture electronic devices and tiny mechanical parts.

Purdue researchers are pursuing the technology for pharmaceutical manufacturing, Wereley said, because a number of drugs are manufactured from solid particles suspended in liquid. The particles have to be collected and separated from the liquid. This process is now done using filters and centrifuges.

REP also might be used to diagnose the presence of viruses, as well, although it has not yet been used to separate viruses from a sample, Wereley said.

Unlike conventional tools, REP requires only tiny samples, making it potentially practical for medical diagnostics and laboratory analysis.

Note to Journalists: An electronic copy of the research paper is available from the journal or by contacting Emi Venere, Purdue News Service.

Writer: Emil Venere

Sources:

Steven T. Wereley, 765-494-5624, wereley@purdue.edu
Joseph Irudayaraj, 765-494-0388, josephi@purdue.edu
Aloke Kumar, 865-574-8661, alokek@gmail.com
Related websites:
Steven T. Wereley: http://engineering.purdue.edu/~wereley
Joseph Irudayaraj: https://engineering.purdue.edu/Engr/People/ptProfile?resource_id=33001
Lab on a Chip magazine: http://blogs.rsc.org/lc/
Lab on a Chip on Twitter: http://twitter.com/LabonaChip
IMAGE CAPTION:
Researchers have demonstrated a new technology that combines a laser and electric fields to create tiny centrifuge-like whirlpools to separate particles and microbes by size, a potential lab-on-a-chip system for medicine and research. Here the technique is used to collect a bacterium called Shewanella oneidensis. (Purdue University)

A publication-quality image is available at http://www.purdue.edu/uns/images/2013/wereley-biochip.jpg.

IMAGE CAPTION TWO:

Here the technique, called rapid electrokinetic patterning, is used to arrange the bacteria into a speific pattern. The technique may be used as a tool for nanomanufacturing because it shows promise for the assembly of suspended particles, called colloids. The ability to construct objects with colloids makes it possible to create structures with particular mechanical and thermal characteristics to manufacture electronic devices and tiny mechanical parts. (Purdue University)

A publication-quality image is available at http://www.purdue.edu/uns/images/2013/wereley-biochip2.jpg.

ABSTRACT

Opto-electrokinetic manipulation for high-performance on-chip bioassays

Jae-Sung Kwon,a Sandeep P. Ravindranath,b Aloke Kumar,c Joseph Irudayarajb and Steven T. Wereley*a

a School of Mechanical Engineering and Birck Nanotechnology Center, Purdue University

b School of Agricultural and Biological Engineering and Bindley Bioscience Center, Purdue University

c Biosciences Division, Oak Ridge National Laboratory

This communication first demonstrates bio-compatibility of a recently developed opto-electrokinetic manipulation technique, using microorganisms. Aggregation, patterning, translation, trapping and size-based separation of microorganisms performed with the technique firmly establishes its usefulness for development of a high-performance on-chip bioassay system. process. Ultimately fast and precise on-chip manipulation of microorganisms aids in development of high-performance bioassay systems.

Emil Venere | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>