Claims
- 1. A method of concentrating a material, comprising:
providing at least first and second channel portions, wherein the second channel portion intersects and being in fluid communication with the first channel portion, the first channel portion having at least first and second fluid regions disposed therein, the first fluid region comprising the material and having a conductivity that is lower than the second fluid, the first and second fluids being in contact at a first substantially static interface; and applying an electric field through the first and second fluid regions in the first channel portion to concentrate the material at the first substantially static interface.
- 2. The method of claim 1, wherein the first static interface is provided substantially at a first fluid junction between the first channel portion and the second channel portion.
- 3. The method of claim 2, wherein at least the second channel portion is provided with a separation matrix disposed therein.
- 4. The method of claim 1, further comprising providing a third channel portion in fluid communication with the first channel portion.
- 5. The method of claim 2, wherein the third channel portion is in fluid communication with the first channel portion substantially at the first fluid junction.
- 6. The method of claim 2, further comprising providing a fourth channel portion in fluid communication with the first channel portion.
- 7. The method of claim 1, wherein the material is positively charged.
- 8. The method of claim 1, wherein the material is negatively charged.
- 9. The method of claim 2, wherein the material comprises nucleic acids.
- 10. The method of claim 2, wherein the material comprises polypeptides.
- 11. The method of claim 2, wherein the material comprises a negatively charged micellar formulation.
- 12. The method of claim 1, wherein the material is provided in a mixture of different materials.
- 13. The method of claim 1, wherein the applying step comprises applying an electric field of a sufficient size and for a sufficient duration to concentrate the material at least 2 fold.
- 14. The method of claim 1, wherein the applying step comprises applying an electric field of a sufficient size and for a sufficient duration to concentrate the material at least 5 fold.
- 15. The method of claim 1, wherein the applying step comprises applying an electric field of a sufficient size and for a sufficient duration to concentrate the material at least 10 fold.
- 16. The method of claim 1, wherein the applying step comprises applying an electric field of a sufficient size and for a sufficient duration to concentrate the material at least 100 fold.
- 17. The method of claim 1, wherein the step of providing the comprises maintaining the first static interface in position by applying pressure to at least one of the first and second fluid regions to maintain the first static interface in a substantially static position within the first channel portion.
- 18. The method of claim 1, wherein during the applying step, there is substantially no electroosmotic flow in the first channel portion.
- 19. The method of claim 2, wherein an interior surface of the first channel portion is treated to reduce a zeta-potential of the surface.
- 20. The method of claim 2, wherein the first channel portions comprises a surface coating which masks a surface charge within the first channel portion.
- 21. The method of claim 2, wherein the first channel portion comprises a dynamic coating material disposed therein.
- 22. The method of claim 1, wherein the second channel portion is in fluid communication with the first channel portion at a first fluid junction.
- 23. The method of claim 2, wherein the substantially static fluid interface is maintained substantially at the first fluid junction.
- 24. The method of claim 2, further comprising the step of moving the material concentrated at the first fluid interface into the second channel portion.
- 25. The method of claim 2, wherein the material is moved into the second channel portion electrokinetically.
- 26. The method of claim 2, wherein the material is moved into the second channel portion electrophoretically.
- 27. The method of claim 2, wherein the providing step further comprises providing a third channel portion in fluid communication with the first and second channel portions at the first fluid junction.
- 28. The method of claim 2, wherein the substantially static fluid interface is maintained substantially at the first fluid junction.
- 29. The method of claim 1, wherein the first conductivity is more than 10% lower than the second conductivity.
- 30. The method of claim 1, wherein the first conductivity is more than 20% lower than the second conductivity.
- 31. The method of claim 1, wherein the first conductivity is more than 50% lower than the second conductivity.
- 32. The method of claim 1, wherein the first conductivity is more than 75% lower than the second conductivity.
- 33. The method of claim 1, wherein the first conductivity is more than 90% lower than the second conductivity.
- 34. The method of claim 1, wherein in the applying step, a voltage gradient across the first fluid region is at least twice as great as a voltage gradient across the second fluid region.
- 35. The method of claim 1, wherein in the applying step, a voltage gradient across the first fluid region is at least 5 times greater than a voltage gradient across the second fluid region.
- 36. The method of claim 1, wherein in the applying step, a voltage gradient across the first fluid region is at least 10 times greater than a voltage gradient across the second fluid region.
- 37. A method of concentrating a material, comprising:
providing a first channel portion having at least first and second fluid regions disposed therein, the material having a first electrophoretic velocity in the first fluid region, and having a second electrophoretic velocity in the second fluid region, wherein the second electrophoretic velocity is less than the first electrophoretic velocity as a result of a different ionic make up of the first and second fluid regions, the first and second fluids being in contact at a first substantially static interface; and electrophoresing the sample material through the first fluid region in the first channel portion toward the second fluid region, the sample material concentrating at the first substantially static interface.
- 38. A system for concentrating a material, comprising:
a first channel portion having a first fluid region disposed therein and a second channel portion having a second fluid region disposed therein, wherein the first and second channel regions are connected at a first fluid junction, the first fluid region comprising the material and having a conductivity that is lower than the second fluid region, the first and second fluid regions being in contact at a first substantially static fluid interface; and an electrical power supply operably coupled to the first channel portion for applying an electric field through the first and second fluid regions in the first channel portion, to concentrate the material at the first substantially static interface.
- 39. The system of claim 2, further comprising a third channel portion connected to the first and second channel portions at the first fluid junction, the first fluid interface being located substantially at the first fluid junction.
- 40. The system of claim 2, wherein each of the second and third channel portions comprise a fluid having a conductivity that is greater than the first fluid region.
- 41. The system of claim 2, further comprising a fluid direction system coupled to at least the second and third channel portions for maintaining the first fluid interface in a substantially static position substantially at the first fluid junction.
- 42. The system of claim 2, wherein the fluid direction system comprises at least first and second pressure sources coupled to the second and third channel portions, respectively, for controlling flow of fluid within the second and third channel portions.
- 43. The system of claim 2, further comprising a fourth channel portion that is in fluid communication at the first fluid junction.
- 44. The system of claim 2, wherein each of the second, third and fourth channel portions comprise a fluid having a conductivity that is greater than the first fluid region.
- 45. A method of concentrating a material, comprising:
providing a first fluid conduit that is intersected by at least a second fluid conduit at a first point; bulk flowing a fluid through the first fluid conduit in a first direction at a first velocity; electrophoretically introducing a material into the first fluid conduit from the second fluid conduit; and electrophoresing the sample material in a second direction in the first conduit and at a second velocity through the fluid in the first fluid conduit, wherein the second direction is opposite to the first direction and the second velocity is greater than or equal to the first velocity, to concentrate the material in the first fluid conduit.
- 46. The method of claim 2, further comprising providing a third fluid conduit intersecting the first fluid conduit at a second point, the second and third fluid conduits being operably coupled to an electrical power supply for generating an electric field between the second and third fluid conduits via the first fluid conduit.
- 47. The method of claim 2, wherein the bulk flowing of fluid in the first channel comprises applying a pressure differential along a length of the first fluid conduit.
- 48. The method of claim 2, wherein the pressure differential is applied by applying a negative pressure at one terminus of the first fluid conduit.
- 49. The method of claim 2, wherein the pressure differential is applied by applying a positive pressure to at least one terminus of the first fluid conduit.
- 50. The method of claim 2, wherein the second velocity is greater than the first velocity.
- 51. The method of claim 2, wherein the material concentrated in the first fluid conduit is subjected to one or more additional analysis steps.
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. provisional patent application No. 60/244,807, filed Oct. 31, 2000, the entire disclosure of which is hereby incorporated herein by reference in its entirety for all purposes.
Provisional Applications (1)
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Number |
Date |
Country |
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60244807 |
Oct 2000 |
US |