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.
Wiebe van der Veen | alfa
New findings help to better calculate the oceans’ contribution to climate regulation
14.11.2018 | Jacobs University Bremen gGmbH
How algae and carbon fibers could sustainably reduce the athmospheric carbon dioxide concentration
14.11.2018 | Technische Universität München
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly
The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
14.11.2018 | Life Sciences
14.11.2018 | Life Sciences
14.11.2018 | Earth Sciences