Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

On chip separation: large molecules pass the speed camera first

10.12.2002


What molecule or particle passes the finishline first? A good way to split a fluid sample into its separate parts is: organize a contest in a micro-channel. The largest parts will pass the optical detector first, the smaller ones follow at short distance. This principle of ‘hydrodynamic chromatography’ is now also possible on a chip. ‘On-chip’ separation is faster, needs tiny samples and uses minimum of harmful solvents. Marko Blom developed this separation chip within the MESA+ research institute of the University of Twente. He presents his PhD-work on December 13, 2002.



The separation channel Blom has developed is not deeper than one micron, it is one millimeter in width and some six to eight centimeters long. It has been fabricated in silicon or silicate glass. Thanks to this compact geometry, the separation is fast: bigger molecules move faster, smaller ones follow. A light-sensitive cell detects the fastest ones first. Colour characteristics provide additional information about the particle or molecule: therefore at the start of the ‘race’, fluorescent markers can be added to the fluid, for example.

Hydrodynamic chromatography (HDC) is a well-known separation technique for particles and large molecules, but the resolution of current methods is far from optimal. HDC is usually applied in a fluid column, filled with non-porous particles that create, with the tiny spaces inbetween, the same effect as a narrow channel. On-chip separation results in a better resolution because the geometry is better defined than the pores between the particles in a conventional column, that are divided in a rather arbitrary way. Within just a few minutes Blom can, for example, fully separate little polystyrene balls. The new chip is particularly interesting for analysis of large molecules like polymers. For biomolecules, it works as well: for example analysis of DNA-components.


Lab-on-chip
A microsystem like this new separation chip has more advantages than the ones mentioned above: it is possible to add all kinds of functionality. It is not just the separation itself that takes place on-chip, but also detection and fluid preparation can be done. Blom has built a with a viscosity sensor: a small bridge over the channel slightly disturbs the fluid. The difference in pressure can be detected optically. The system is a new lab-on-chip, systems that are for large amounts of analyses at the same time.

Blom’s research is part of the research orientation MicroChemical Systems, within the MESA+ research institute of the University of Twente in The Netherlands (www.mesaplus.utwente.nl). It has been financially supported by the Dutch Technology Foundation STW (www.stw.nl). Blom has done his research in close cooperation with the Polymer Analysis group of the University of Amsterdam.

Wiebe van der Veen | alfa

More articles from Life Sciences:

nachricht New application for acoustics helps estimate marine life populations
16.01.2018 | University of California - San Diego

nachricht Unexpected environmental source of methane discovered
16.01.2018 | University of Washington Health Sciences/UW Medicine

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Gran Chaco: Biodiversity at High Risk

17.01.2018 | Ecology, The Environment and Conservation

Only an atom thick: Physicists succeed in measuring mechanical properties of 2D monolayer materials

17.01.2018 | Physics and Astronomy

Fraunhofer HHI receives AIS Technology Innovation Award 2018 for 3D Human Body Reconstruction

17.01.2018 | Awards Funding

VideoLinks
B2B-VideoLinks
More VideoLinks >>>