LabAutomation 2006 - SLAS

LabAutomation2006
12:00 pm Tuesday, January 24, 2006 Track 2: Micro- and Nanotechnologies Room: Pasadena
Wyndham Palm Springs Hotel
Goetz Muenchow
Co-Author(s)
Institut für Mikrotechnik Mainz GmbH
Klaus Stefan Drese
Mainz, Germany
Institut für Mikrotechnik Mainz GmbH
muenchow@imm-mainz.de
Steffen Hardt
Darmstadt University of Technology
Joerg P. Kutter
Technical University of Denmark
F I N A L I S T
Electrophoretic Partitioning of Proteins in Two-Phase Microflows
The presented work is concerned with the transport of biomolecules, here BSA (bovine serum albumin), inside microchannels influenced
by an electric field over the channel width in combination with a two-phase configuration of fluid layers. A major goal of these studies is to
establish a new separation and concentration mode for biomolecules by superposing electrophoretic separation along a microchannel with
electro-mediated transfer between two phases perpendicular to that. The device consists of a microchannel embedded in COC (cycloolefin
copolymer) and two wall electrodes. In a first step, the use of such a set-up is explored by studying the electrophoretic transport
of BSA molecules dissolved in water, which leads to an increased concentration on either one or the other electrode, depending on the
direction of the electric field.
In order to investigate the transport phenomena related to electrophoresis in stratified two-phase systems, aqueous solutions consisting of
PEG (polyethylene glycol) and Dextran were prepared. By that a stable interface was developed. Transportation within one phase and also
a concentration of BSA proteins at the phase boundary has been established. The effects occurring in a system containing two immiscible
liquids are currently being investigated in more detail. For this purpose immiscible phases of PEG/Dextran solutions as well as other fluid
combinations such as water/oil and water/alcohol are used. The final goal of our work is to utilize these effects for novel microsystembased
separation and enrichment techniques for biomolecules.
3:00 pm Tuesday, January 24, 2006 Track 2: Micro- and Nanotechnologies Room: Pasadena
Wyndham Palm Springs Hotel
R. Scott Martin
Saint Louis University
St. Louis, Missouri
martinrs@slu.edu
Coupling Valving and Microchip-Based Separations for Analyzing Neurotransmitters
Released From Cells
The use of microchip technology to perform on-chip cell culture is a rapidly emerging area. To investigate the mechanisms of neuronal
degeneration and the exact role nitric oxide plays in this process it is highly desirable to develop a device that combines a model of
dopaminergic cells (such as PC 12 cells) and an analysis system to monitor the cell’s exocytotic activity. In this talk, we will describe the
use of poly(dimethylsiloxane) (PDMS) –based microvalves to control both the on-chip culture of cells and the coupling of a cell reactor to
an analysis system (such as capillary electrophoresis). We will describe the use of capillary electrophoresis with amperometric detection to
monitor the release of dopamine and norepinephrine from an immobilized PC 12 cell reactor. The ability to couple the PC 12 cell reactor to
an analysis system with minimal dead volume on a planar substrate leads to a true micro-total analysis system that can be used to study
the role of nitric oxide in the onset of Parkinson’s disease. We are also using microvalves to direct the on-chip culture of endothelial cells
in a three-dimensional fluidic device to create an in vitro blood-brain barrier mimic. These studies demonstrate the advantages of using
microchips and PDMS-based valving techniques to develop a system that can integrate cell immobilization, cell stimulation, manipulation of
chemicals released from the cells, and analysis of the chemicals.
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