Method and apparatus for fractionation using generalized dielectrophoresis and field flow fractionation

• US 5,888,370 A
• Filed: 02/23/1996
• Issued: 03/30/1999
• Est. Priority Date: 02/23/1996
• Status: Expired due to Term

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Huang, Ying, Becker, Frederick F., Gascoyne, Peter R. C., Wang, Xiao-Bo
• Primary Examiner(s): Achutamurthy, Ponnathapura
• Assistant Examiner(s): PONNALURI, PADMASHRI
• Application Number:
  US08/605,535
• Time in Patent Office: 1,131 Days
• Field of Search: 204/547, 204/643, 435/34, 435/173.9, 435/287.1, 435/284.1
• US Class Current: 204/643
• CPC Class Codes: B03C 5/028 using travelling electric fields, i.e. travelling wave dielectrophoresis [TWD]
• CPC Class Codes: G01N 2030/0035 electrical field
• CPC Class Codes: G01N 2030/0065 Dielectric FFF, i.e. opposing forces dominate hydrodynamic lift forces and steric effects
• CPC Class Codes: G01N 30/0005 Field flow fractionation

Abstract

The present disclosure is directed to a novel apparatus and novel methods for the separation, characterization, and manipulation of matter. In particular, the invention combines the use of frequency-dependent dielectric and conductive properties of particulate matter and solubilized matter with the properties of the suspending and transporting medium to discriminate and separate such matter. The apparatus includes a chamber having at least one electrode element and at least one inlet and one output port into which cells are introduced and removed from the chamber. Matter carried through the chamber in a fluid stream is then displaced within the fluid by a dielectrophoretic (DEP) force caused by the energized electrode. Following displacement within the fluid, matter travels through the chamber at velocities according to the velocity profile of the chamber. After the matter has transitted through the chamber, it exits at the opposite end of the chamber at a characteristic position. Methods according to the invention involve using the apparatus for discriminating and separating matter for research, diagnosis of a condition, and therapeutic purposes. Examples of such methods may include separation of mixtures of cells, such as cancer cells from normal cells, separation of parasitized erythrocytes from normal erythrocytes, separation of nucleic acids, and others.

Claims

1. An apparatus for the discrimination of matter utilizing dielectrophoresis and field flow fractionation, comprising:

a) a chamber having an inlet port and a plurality of outlet ports, said chamber having an interior surface and an exterior surface, said chamber further having a substantially greater width than thickness which causes fluid traveling through said chamber to travel at different velocities according to a velocity profile;

b) a plurality of electrode elements adapted along a portion of said chamber, wherein the plurality of electrode elements comprise an electrode array; and

c) wherein said plurality of electrode elements energized at different phases by electrical signals provided by an electrical signal generator creates a traveling electric field, thereby causing a dielectrophoretic force on said matter having components normal to the direction of said fluid traveling through said chamber, said dielectrophoretic force displaces said matter to varying distances in said velocity profile and in a plane parallel with respect to said plurality of electrode elements such that said matter is not collected on said plurality of electrode elements.

2. The apparatus according to claim 1, wherein said plurality of outlet ports are vertically lower than said inlet port, thereby permitting discrimination of said matter by sedimentation.

3. The apparatus according to claim 1, wherein said dielectrophoretic force acts solely in a direction normal to said fluid traveling through said chamber.

4. The apparatus according to claim 1, wherein each of said plurality of electrode elements is individually connected to one of a plurality of electrical conductors electrically connected to said electrical signal generator.

5. The apparatus according to claim 1, wherein said energized plurality of electrode elements further creates a spatially inhomogeneous electric field.

6. The apparatus according to claim 1, wherein said positions of said matter within said fluid causes said matter to travel through said chamber at velocities according to said velocity profile.

7. The apparatus according to claim 1, wherein said matter exits from said plurality of outlet ports at time intervals proportionate to its position within said velocity profile.

8. The apparatus according to claim 1, wherein said matter exits from said plurality of outlet ports at positions laterally displaced from said inlet port.

9. The apparatus according to claim 1 wherein the velocity profile is a hydrodynamic fluid profile.

10. The apparatus according to claim 7, wherein the hydrodynamic fluid profile is a parabolic flow profile.

11. The apparatus according to claim 1, wherein said dielectrophoresis comprises conventional dielectrophoresis.

12. The apparatus according to claim 1, wherein said dielectrophoresis comprises traveling wave dielectrophoresis.

13. The apparatus according to claim 1, wherein said dielectrophoresis comprises generalized dielectrophoresis.

14. The apparatus according to claim 1, wherein said chamber comprises a tube.

15. The apparatus according to claim 12, wherein said plurality of electrode elements is adapted along the interior surface of said tube.

16. The apparatus according to claim 12, wherein said plurality of electrode elements is adapted along the exterior surface of said tube.

17. The apparatus according to claim 1, wherein the chamber includes a top wall, a bottom wall, and two side walls.

18. The apparatus according to claim 1, wherein said matter comprises particulate matter.

19. The apparatus according to claim 16, wherein the particulate matter is selected from the group consisting of a cell, cell aggregate, cell organelle, nucleic acid, bacteria, protozoan, and virus.

20. The apparatus according to claim 1, wherein said matter comprises solubilized matter.

21. The apparatus according to claim 18, wherein the solubilized matter is selected from the group consisting of a molecule, molecular aggregate, and molecule mixture.

22. The apparatus according to claim 19, wherein the molecule or molecular aggregate is selected from the group consisting of a protein and a protein mixture.

23. The apparatus according to claim 1, wherein the plurality of electrode elements are adapted substantially longitudinally along a portion of said chamber.

24. The apparatus according to claim 1, wherein the plurality of electrode elements are adapted substantially latitudinally along a portion of said chamber.

25. The apparatus according to claim 1, wherein the plurality of electrode elements are adapted along the interior surface of said chamber.

26. The apparatus according to claim 1, wherein the plurality of electrode elements are adapted along the exterior surface of said chamber.

27. The apparatus according to claim 1, wherein a ratio of electrode element width to electrode element spacing is modified to change levitation heights of said matter.

28. The apparatus of claim 1, wherein said plurality of electrode elements are configured on a plane substantially normal to a flow of said fluid travelling through said chamber.

29. The apparatus of claim 1, wherein said plurality of electrode elements are configured on a plane substantially parallel to a flow of said fluid travelling through said chamber.

30. The apparatus of claim 1, wherein said plurality of outlet ports are connected to a fraction collector.

31. The apparatus of claim 1, wherein said plurality of outlet ports are connected to collection wells.

32. The apparatus according to claim 1, wherein the electrode array is configured on a top wall of said chamber.

33. The apparatus according to claim 1, wherein the electrode array is configured on a bottom wall of said chamber.

34. The apparatus according to claim 1, wherein a plurality of said electrode arrays are adapted on opposing surfaces of said chamber.

35. The apparatus according to claim 1, wherein a plurality of said electrode arrays are adapted on opposing surfaces of said chamber such that each of said electrode elements is not directly opposed by another said electrode element on said opposing surface.

36. The apparatus according to claim 1, wherein said velocity profile is in a substantially horizontal plane.

37. The apparatus according to claim 1, wherein said electrical signal generator is capable of varying magnitude, or frequency, and phase of said electrical signals.

38. The apparatus according to claim 1, wherein more than two electrical signals having different phases are provided by said electrical signal generator.

39. An apparatus for the discrimination of matter, comprising:

a) a chamber having an inlet port and a plurality of outlet ports, said chamber having an interior surface and an exterior surface, a top wall, a bottom wall and two side walls, said chamber having a substantially greater width than thickness which causes fluid traveling through said chamber to travel at different velocities according to a velocity profile;

b) an electrode array adapted along a portion of each of at least two said walls in opposing relation, each of said electrode arrays electrically connected to electrical conductors;

c) a duct entering the chamber, said duct capable of introducing said fluid to carry said matter from an inlet port of said chamber to a plurality of outlet ports of said chamber;

d) an electrical signal generator electrically connected to said electrical conductors; and

e) wherein said electrode arrays energized at different phases by electrical signals provided by said electrical signal generator create a traveling electric field in said chamber, thereby causing a dielectrophoretic force on said matter to displace said matter to varying distances in said velocity profile with respect to said electrode arrays, and to displace said matter parallel to said electrode arrays such that said matter is not collected on said electrode arrays.

40. An apparatus according to claim 39, wherein said inlet port is adapted in close relation to said top wall.