Movement of particles using sequentially activated dielectrophoretic particle trapping

• US 20020088712A1
• Filed: 01/09/2001
• Published: 07/11/2002
• Est. Priority Date: 01/09/2001
• Status: Active Grant

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Miles, Robin R.
• Granted Patent: US 6,685,812 B2
• Time in Patent Office: Days
• US Class Current: 204/547
• CPC Class Codes: B01L 2200/0668 Trapping microscopic beads
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0867 Multiple inlets and one sample wells, e.g. mixing, dilution
• CPC Class Codes: B01L 2300/0877 Flow chambers
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0424 Dielectrophoretic forces
• CPC Class Codes: B01L 3/502761 specially adapted for handling suspended solids or molecules independently from the bulk fluid flow, e.g. for trapping or sorting beads, for physically stretching molecules investigating characteristics of particles G01N15/00
• CPC Class Codes: B03C 5/028 using travelling electric fields, i.e. travelling wave dielectrophoresis [TWD]
• CPC Class Codes: Y10T 436/25 including sample preparation

Abstract

Manipulation of DNA and cells/spores using dielectrophoretic (DEP) forces to perform sample preparation protocols for polymerized chain reaction (PCR) based assays for various applications. This is accomplished by movement of particles using sequentially activated dielectrophoretic particle trapping. DEP forces induce a dipole in particles, and these particles can be trapped in non-uniform fields. The particles can be trapped in the high field strength region of one set of electrodes. By switching off this field and switching on an adjacent electrodes, particles can be moved down a channel with little or no flow.

Claims

1. In a sample preparation system using a fluidic channel and dielectrophoretic forces, the improvement comprising:

controlling movement of sample particles along the fluidic channel by sequentially activated dielectrophoretic particle trapping.

2. The improvement of claim 1, wherein the movement of sample particles by particle trapping is carried out by producing sequential electric fields along a length of the fluidic channel.

3. The improvement of claim 2, wherein the sequential electric fields are produced by a plurality of electrodes operatively connected to an AC power supply via a switching mechanism.

4. The improvement of claim 3, wherein said plurality of electrodes comprises at least one electrode configuration having a single electrode on one surface of the fluidic channel and a series of electrodes on another surface of the fluidic channel.

5. The improvement of claim 4, wherein said AC power supply is connected to said single electrode and sequentially connected to each electrode of said series of electrodes, whereby a series of electric fields are created along a length of the fluidic channel.

6. The improvement of claim 5, wherein said single electrode is located at the bottom of the fluidic channel and the series of electrodes are located at the top of the fluidic channel, or vice versa.

7. The improvement of claim 5, wherein said fluid channel is provided with a plurality of said electrode configurations in spaced relation along a length of said fluidic channel.

8. A method for manipulation of DNA and cells/spores using dielectrophoretic forces to perform sample preparation protocols for PCR based assays, comprising:

providing a flow channel, and

controlling of movement of sample particles through the flow channel using sequentially activated dielectrophoretic particle trapping.

9. The method of claim 8, wherein the sequentially activated dielectrophoretic particle trapping is carried out by forming sequential electric fields along a length of the flow channel such that the sample particles are movement from one electric field to an adjacent downstream electric field.

10. The method of claim 9, wherein forming of the sequential electric fields is carried out by sequentially activating and deactivating a series of electrode positioned along a length of the flow channel.

11. The method of claim 10, additionally including forming the series of electrodes by photolithographically patterning the electrodes on the top and bottom of the flow channel.

12. The method of claim 10, wherein the series of electrodes are forming to define a single electrode on one surface of a flow channel and a plurality of electrodes on an opposite surface of the flow channel.

13. The method of claim 12, wherein a power supply is electrically connected to the single electrode and sequentially connected to the plurality of electrodes for producing sequential electric fields therebetween, whereby a sample particle is moved along a length of the flow channel by the sequential electric fields.

14. The method of claim 13, additionally including forming a plurality of spaced electrode configuration along a length of the flow channel, each electrode configuration having a single electrode on one surface of the flow channel and a plurality of electrodes on an opposite surface of the flow channel, and providing means to direct an electric signal to the single electrode and to selectively direct an electric signal to one or more of the plurality of electrodes for generating or removing electric fields along a length of the flow channel.

16. The improvement of claim 15, wherein said means includes a plurality of patterned electrode on a surface of the fluid channel and a single electrode one an opposite surface of the fluid channel, and a power supply connected to said single electrode and sequentially connected to said plurality of patterned electrodes.

17. The improvement of claim 16, wherein said means additionally includes a mechanism for sequentially connecting said power supply to said plurality of electrodes, whereby deactivation of one electrode and activation of an adjacent electrode produces a sequence of electric fields along the fluid channel causing controlled movement of trapped samples along the fluid channel.

18. The improvement of claim 17 wherein said power supply comprises an AC power source.

19. The improvement of claim 15, including a plurality of electrode configuration spaced along a length of the fluid channel, each electrode configuration operatively connected to a power supply to produce selective electric fields between electrodes of each electrode configuration, for trapping, moving, and/or concentrating samples in the fluid channel.

15. In a system for PCR sample preparation comprising a fluid channel through which samples are directed, the improvement comprising means for controlling movement of the samples through the fluid channel using sequentially activated dielectrophoretic particle trapping.