Continuous Fractionation of DNA Using Asymmetric Pulsed Field Electrophoresis on Micro/Nano-Fabricated Matrices

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Researchers at Princeton University have developed three new methods for manipulation of DNA and other large macromolecules in microfluidic environments.  


The first method permits fractionation of DNA continuously on micro or nano-fabricated support materials.  Current methods to fractionate larger (greater than 30kb) DNA molecules by size use pulsed gel electrophoresis and typically take several days to fractionate one set of samples.  This new method uses micro or nano fabricated environments to accurately control the motion of the DNA molecules, allowing continuous fractionation with very high resolution in a matter of seconds, even for DNA molecules larger than 100kbp.


The second method permits generation of a wide variety of electrical field distributions in the electrolyte layer of micro-fabricated electrophoretic devices.   Pulsed field gel electrophoresis, which is currently used to fractionate large DNA molecules, requires a uniform, homogeneous alternate electric field.  This is performed in standard electrophoresis setups using multiple electrodes, however, this method is not practical in microfluidic applications as it requires a multitude of electrodes, electrolyte reservoirs, complex driving circuits, and can create undesirable bubbles at the electrode/electrolyte interface.   This new method permits the generation of many types of electrical fields, while minimizing bubble generation and the number of electrodes, thereby increasing the reliability of such microfluidic devices.


The third method allows the generation of a wide variety of flow distributions of a layer of liquid in micro-fluidic devices.  Current methods require the use of numerous pressure regulators to control the flow distribution in a layer of liquid, and may not be practical in microfluidic applications, due to complexity, instability and cost.  This new method employs pressure sources in series with microfluidic channels to generate two-dimensional flow distributions.


It is anticipated that these methods will be useful in any application using microfluidics or lab-on-a-chip technologies.  Patent protection is pending.

Patent Information:
For Information, Contact:
William Gowen
Licensing Associate
Princeton University
James Sturm
Lotien Huang
Robert Austin