Method of simultaneously concentrating and separating analytes

• US 20030094369A1
• Filed: 09/30/2002
• Published: 05/22/2003
• Est. Priority Date: 10/01/2001
• Status: Abandoned Application

• Current Assignee: Brigham Young University (The Church of Jesus Christ of Latter-Day Saints)
• Original Assignee: Brigham Young University (The Church of Jesus Christ of Latter-Day Saints)
• Inventors: LeFebre, David A., Wang, Qinggang, Lee, Milton L., Tolley, H. Dennis
• Application Number:
  US10/260,898
• Publication Number:
  US 20030094369A1
• Time in Patent Office: Days
• US Class Current: 204/450
• CPC Class Codes: G01N 27/44769 Continuous electrophoresis, i.e. the sample being continuously introduced, e.g. free flow electrophoresis [FFE]

Abstract

A method and apparatus are disclosed for simultaneously concentrating and separating a plurality of analytes which includes generating a continuous electric field gradient within an enclosed passageway, and where the electric field gradient is characterized by the graph of the gradient with respect to position along the length of the axis of the passageway being a non-linear, monotone, non-decreasing function with a non-increasing first derivative. Analytes entrained in a carrier fluid within the passageway are exposed simultaneously to the continuous electrical field gradient and an opposing force selected for exerting a force on the analytes. The analytes are allowed to reach equilibrium with respect to the continuous electric field gradient and the opposing force, then are released in a controlled manner to maintain separation. The unique shape of the electric field intensity curve allows for simultaneous concentration and separation of analytes.

Claims

1. A method of concentrating and separating, in a specific order, a plurality of analytes, comprising:

generating a continuous electric field gradient within a passageway enclosed with respect to the analytes, the gradient being characterized by the graph of the gradient with respect to position along the length of the axis of the passageway being a non-linear, monotone, non-decreasing function with a non-increasing first derivative;

exposing a carrier fluid, including a plurality of analytes and located within the passageway, simultaneously to the continuous electrical field gradient and an opposing force, the opposing force being selected for exerting a balancing force on at least one of the analytes;

allowing the analytes to approach or reach equilibrium with respect to the continuous electric field gradient and the opposing force; and

automatically releasing the analytes in a controlled manner to maintain separation.

2. The method of claim 1, wherein the opposing force in said exposing step is a centrifugal, gravitational, magnetic, thermal, acoustic, hydrodynamic, electroosmotic or electromagnetic force.

3. The method of claim 1, wherein the opposing force is a combination of forces.

4. The method of claim 1, wherein the continuous gradient of said generating step varies due to the use of at least one of the group consisting of a varying cross sectional area of the passageway, a distributed resistor or a semi-permeable membrane along at least a portion of the passageway.

5. The method of claim 1 further comprising an introducing step comprising injecting the analytes as a fluid or entrained in a carrier fluid, using a syringe, valve or any other fluid dispensing device.

6. The method of claim 1, wherein the carrier fluid comprises a mixture of fluids.

7. The method of claim 6, wherein the carrier fluid includes at least one of polymers and electrolytes.

8. The method of claim 1, wherein the passageway is a microchannel.

9. The method of claim 1, wherein the passageway has an entry port and an exit port and said generating step further comprises applying one of two electrodes having a constant voltage differential to each of the entry port and the exit port.

10. The method of claim 1, wherein said generating step further comprises selecting the slope of the gradient to optimize the degree of concentration and separation of the analytes.

11. The method of claim 9, wherein said releasing step comprises a series of steps whereby each step comprises removing the separated analytes, reducing the voltage differential and allowing the analytes to approach or reach equilibrium with respect to the continuous electric field gradient and the opposing force.

12. The method of claim 9, wherein said releasing step comprises changing the balance between the continuous electric field gradient and the opposing force such that the separated analytes move toward the exit port.

14. The method of claim 1 wherein said analytes comprise at least one of proteins, lipoproteins, nucleic acids, peptides and carbohydrates.

15. The method of claim 1 further comprising diagnostic testing utilizing one or more of the separated analytes.

16. The method of claim 1 wherein the source of the analyte is a biological organism.

13. The method of clam 1, further comprising automatically controlling at least one of the voltage differential, at least one opposing force and said releasing of the analytes.

17. A method of concentrating and separating, in a specific order, a plurality of analytes, comprising:

generating a continuous electric field gradient within a passageway enclosed with respect to the analytes, the gradient being characterized by the graph of the gradient with respect to position along the length of the axis of the passageway being a non-linear, monotone, non-decreasing function with a non-increasing first derivative;

exposing a carrier fluid, including a plurality of analytes and located within the passageway, simultaneously to the continuous electrical field gradient and an opposing force, the opposing force being selected for exerting a balancing force on at least one of the analytes;

allowing the analytes to reach or approach equilibrium with respect to the continuous electric field gradient and the opposing force;

releasing the analytes in a controlled manner to maintain separation; and

determining properties or fingerprint information by further separating, identifying or analyzing at least one of the analytes.

18. The method of claim 17, wherein said determining step utilizes using at least one of chromatography, electrophoresis, mass spectrometry or other means for separating analytes.

19. The method of claim 17, wherein the passageway is packed with particles or monolithic material along at least a portion of its length.

20. A method of concentrating and separating, in a specific order, a plurality of analytes, comprising:

separating at least two of the analytes using a liquid separation;

conducting the analytes directly from the liquid separation to a passageway enclosed with respect to the analytes;

generating a continuous electric field gradient within the passageway, the gradient being characterized by the graph of the gradient with respect to position along the length of the axis of the passageway being a non-linear, monotone, non-decreasing function with a non-increasing first derivative;

exposing a carrier fluid, including a plurality of analytes and located within the passageway, simultaneously to the continuous electrical field gradient and an opposing force, the opposing force being selected for exerting a balancing force on at least one of the analytes;

allowing the analytes to reach equilibrium with respect to the continuous electric field gradient and the opposing force; and

releasing the analytes in a controlled manner to maintain separation.

21. The method of claim 20 wherein said liquid separation is at least one of chromatography, capillary electrophoresis, mass spectrometry or isoelectric focusing.

22. An apparatus for concentrating and separating, in a specific order, a plurality of analytes, comprising:

an enclosed passageway;

a continuous electric field gradient characterized by the graph of said gradient with respect to position along the length of the axis of said passageway being a non-linear, monotone, non-decreasing function with a non-increasing first derivative;

a carrier fluid comprising a plurality of analytes within said passageway;

at least one opposing force acting on said analytes in a direction opposing said gradient that concentrates and separates said analytes when said analytes approach or-reach equilibrium with respect to said gradient and said opposing force; and

a means for automatically changing the equilibrium of said gradient and said opposing force to release said separated analytes in a controlled manner.

23. The apparatus of claim 22, wherein said passageway is packed with particles or monolithic material along at least a portion of its length.

24. The apparatus of claim 22, wherein said passageway is a microchannel.

25. The apparatus of claim 22, comprising a series of passageways operated in a parallel manner.

26. The apparatus of claim 22, wherein said passageway is in contact with a semi-permeable membrane along at least a portion of its length.

27. The apparatus of claim 22, further comprising a computerized control means configured to control at least one of said gradient, said opposing force and injection of a sample including said analytes into said passageway.

28. The apparatus of claim 22, wherein said electric field has a first portion configured for concentrating and ordering said plurality of chemical species and a second portion configured for separating said plurality of chemical species from each other.

29. The device of claim 22 further comprising a control device configured for control of said first continuous field gradient.

30. The device of claim 22, wherein multiple enclosed passageways are operated in parallel.

31. The device of claim 22, wherein multiple enclosed passageways create a microchannel array.

32. The device of claim 22 wherein the passageway has a continuously decreasing cross-sectional area.

33. The device of claim 22 wherein said electric field gradient is created using a distributed resistor.

34. The device of claim 22 wherein said passageway further comprises a gradient channel and a purge channel separated at least in part by a semi-permeable membrane.