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

• US 5,993,630 A
• Filed: 01/31/1996
• Issued: 11/30/1999
• Est. Priority Date: 01/31/1996
• Status: Expired due to Term

• Current Assignee: eAcceleration Corporation
• 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): Till, Terrence R.
• Assistant Examiner(s): STARSIAK, JOHN S
• Application Number:
  US08/604,779
• Time in Patent Office: 1,399 Days
• Field of Search: 204/643, 204/547
• US Class Current: 204/547
• 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 separtion, 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. A method of discriminating matter in a chamber disposed horizontally, said chamber having an inlet port and an outlet port, top and bottom plates, a center and a pair of side walls, and an electrode element, said chamber having a substantially greater distance between said pair of side walls than between said top and bottom plates, utilizing dielectrophoresis and field flow fractionation, comprising:

introducing a carrier medium including said matter into said inlet port such that said carrier medium travels through said chamber horizontally according to a velocity profile such that said carrier medium moves more rapidly at said center than at said top and bottom plates;

balancing a dielectrophoretic force caused by a spatially inhomogeneous electric field created by applying an electrical signal to said electrode element on said matter having components normal to the direction of said carrier medium traveling through said chamber with a gravitational force on said matter to;

displace said matter to positions within said velocity profile in said carrier medium.

2. The method according to claim 1, wherein the matter is discriminated according to said velocity profile and said matter moves within said chamber at velocities proportionate to its displacement within said velocity profile.

3. The method according to claim 1, wherein said displaced matter exits from said outlet port at time intervals proportionate to its said displacement within said velocity profile.

4. The method according to claim 1, wherein said displaced matter exits from said outlet port at positions laterally displaced from said inlet port.

5. The method according to claim 1, wherein said gravitational force acting on said matter acts in a direction normal to said velocity profile.

6. The method according to claim 1, further comprising varying said spatially inhomogeneous electric field, thereby causing changes in displacement of said matter, thereby further discriminating said matter according to its positions within said velocity profile.

7. The method according to claim 1, wherein said method of discrimination is in batch mode.