Method for the manipulation of a fluid sample

• US 7,135,144 B2
• Filed: 04/08/2002
• Issued: 11/14/2006
• Est. Priority Date: 08/13/1997
• Status: Expired due to Fees

• Current Assignee: Cepheid (Danaher Corporation)
• Original Assignee: Cepheid (Danaher Corporation)
• Inventors: Kovacs, Gregory T. A., Petersen, Kurt E., Northrup, M. Allen, McMillan, William A., Pourahmadi, Farzad, Christel, Lee A.
• Primary Examiner(s): Corcoran, Gladys J P
• Assistant Examiner(s): Chorbaji, Monzer R.
• Application Number:
  US10/118,810
• Publication Number:
  US 20020175079A1
• Time in Patent Office: 1,681 Days
• Field of Search: 435/173.9, 422 99-100, 204/600, 204/605, 204450-451, 204/455
• US Class Current: 422/527
• CPC Class Codes: B01F 2025/9171 Parallel flow, i.e. every point of the flow moves in parallel layers where intermixing can occur by diffusion or which do not intermix; Focusing, i.e. compressing parallel layers without intermixing them
• CPC Class Codes: B01F 25/31 in conduits or tubes through which the main component flows
• CPC Class Codes: B01F 25/43231 the channels or tubes crossing each other several times
• CPC Class Codes: B01F 33/30 Micromixers
• CPC Class Codes: B01J 19/0093 Microreactors, e.g. miniaturised or microfabricated reactors laboratory containers with capillary fluid transport in microfabricated channels or chambers B01L3/5027
• CPC Class Codes: B01L 2200/0636 Focussing flows, e.g. to laminate flows
• CPC Class Codes: B01L 2200/0668 Trapping microscopic beads
• CPC Class Codes: B01L 2300/0681 Filter
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 2400/086 using baffles or other fixed flow obstructions
• CPC Class Codes: B01L 3/502753 characterised by bulk separation arrangements on lab-on-a-chip devices, e.g. for filtration or centrifugation separation in general B01D; microapparatus for analysis using electrophoresis G01N27/44791; sample preparation G01N1/28
• CPC Class Codes: C07H 1/00 Processes for the preparation of sugar derivatives
• CPC Class Codes: G01N 1/405 by adsorption or absorption
• CPC Class Codes: G01N 30/6095 Micromachined or nanomachined, e.g. micro- or nanosize
• CPC Class Codes: Y10S 366/03 Micromixers: variable geometry from the pathway influences mixing/agitation of non-laminar fluid flow
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

The invention provides a device and method for the manipulation of materials (e.g., particles, cells, macromolecules, such as proteins, nucleic acids or other moieties) in a fluid sample. The device comprises a substrate having a plurality of microstructures and an insulator film on the structures. Application of a voltage to the structures induces separation of materials in the sample. The device and method are useful for a wide variety of applications such as dielectrophoresis (DEP) or the separation of a target material from other material in a fluid sample.

Claims

1. A method for separating target material from other material in a fluid sample, the method comprising the steps of:

a) forcing the fluid sample to flow through a separation device, the separation device comprising a substrate and a plurality of structures on the substrate, each of the structures being coated with an electrical insulator film;

b) applying a voltage to the structures while the sample flows through the device, thereby attracting the target material to the insulator film while the other material passes through the device; and

c) eluting the target material from the device, wherein the step of eluting the target material is preceded by the step of forcing a wash fluid to flow through the device while maintaining the application of the voltage.

2. The method of claim 1, further comprising the step of pulsing the polarity of the applied voltage.

3. The method of claim 1, wherein the target material comprises nucleic acid, and wherein the voltage comprises an AC voltage tuned to a frequency that facilitates the retention of the nucleic acid.

4. The method of claim 1, wherein the target material is eluted by introducing a carrier fluid into the device, reversing the polarity of the applied voltage to release the target material into the carrier fluid, and flowing the carrier fluid out of the device.

5. The method of claim 1, wherein the target material comprises nucleic acid, a positive voltage is applied to the structures while the sample flows through the device, and the nucleic acid is eluted by introducing a carrier fluid into the device, applying a negative voltage to the structures to release the nucleic acid into the carrier fluid, and flowing the carrier fluid out of the device.

6. The method of claim 1, wherein the target material is eluted by removing the applied voltage and flowing a carrier fluid through the device.

7. The method of claim 1, wherein the structures comprise an array of three-dimensional structures, each of the structures having a height of at least 100 μ

m, and wherein the fluid sample is forced to flow between the structures as the voltage is applied.

8. The method of claim 1, wherein the structures comprise an array of columns, each of the columns having an aspect ratio (height to width or diameter) of at least 2:

1, and wherein the fluid sample is forced to flow between the columns as the voltage is applied.

9. The method of claim 8, wherein the fluid sample is forced to flow in a network of channels between the columns, each of the channels having a width in the range of 5 to 50 μ

m.

10. The method of claim 8, wherein the fluid sample is forced to flow in a network of channels between the columns, each of the channels having a height in the range of10 to 1000 μ

m.

11. The method of claim 1, wherein the insulator film has a thickness in the range of 0.01 to 10 μ

m.

12. The method of claim 11, wherein the insulator film is selected from the group consisting of silicon dioxide, silicon carbide, silicon nitride, and electrically insulating polymer.

13. A method for separating materials in a fluid sample, the method comprising the steps of:

a) introducing the fluid sample into a device having an array of three-dimensional structures, each of the structures having a height of at least 20 μ

m;

b) forcing the fluid sample to flow between the structures while applying a voltage to the structures, thereby inducing separation of materials in the fluid sample as the sample flows between the structures, wherein the materials in the fluid sample are separated by retaining target material in the device while other material in the fluid sample passes out of the device;

c) forcing a wash fluid to flow through the device while maintaining the application of the voltage; and

d) eluting the target material from the device.

14. The method of claim 13, further comprising the step of pulsing the polarity of the applied voltage.

15. The method of claim 13, wherein the target material comprises nucleic acid, and wherein the voltage comprises an AC voltage tuned to a frequency that facilitates the retention of nucleic acid.

16. The method of claim 15, wherein the target material is eluted by introducing a carrier fluid into the device, reversing the polarity of the applied voltage to release the target material into the carrier fluid, and flowing the carrier fluid out of the device.

17. The method of claim 15, wherein the target material comprises nucleic acid, a positive voltage is applied to the structures while the sample flows through the device, and the nucleic acid is eluted by introducing a carrier fluid into the device, applying a negative voltage to the structures to release the nucleic acid into the carrier fluid, and flowing the carrier fluid out of the device.

18. The method of claim 13, wherein the target material is eluted by removing the applied voltage and flowing a carrier fluid through the device.

19. The method of claim 13, wherein each of the structures has a height of at least 100 μ

m.

20. The method of claim 13, wherein the structures comprise an array of columns, each of the columns having an aspect ratio (height to width or diameter) of at least 2:

1.

21. The method of claim 13, wherein the fluid sample is forced to flow in channels disposed between the structures, each of the channels having a width in the range of 5 to 50 μ

m.

22. The method of claim 13, wherein the structures are coated with an insulator film.

23. The method of claim 22, wherein the insulator film has a thickness in the range of 0.01 to 10 μ

m.

24. The method of claim 22, wherein the insulator film is selected from the group consisting of silicon dioxide, silicon carbide, silicon nitride, and electrically insulating polymer.

25. A method for separating target material from other material in a fluid sample, the method comprising the steps of:

a) contacting the sample with an electronic extractor having an insulator film and an underlying conductor in contact therewith, the insulator film having a thickness in the range of 0.01 to 10 μ

m;

b) applying a voltage to the conductor, thereby inducing movement of the target material in the fluid sample to or from the surface of the insulator film, wherein the materials in the fluid sample are separated by retaining the target material in the extractor while the other material in the fluid sample passes out of the extractor;

c) forcing a wash fluid to flow through the extractor while maintaining the application of the voltage; and

d) eluting the target material from the extractor.

26. The method of claim 25, further comprising the step of pulsing the polarity of the applied voltage.

27. The method of claim 25, wherein the voltage comprises an AC voltage tuned to a frequency that facilitates the retention of nucleic acid.

28. The method of claim 25, wherein the target material is eluted by introducing a carrier fluid into the extractor, reversing the polarity of the applied voltage to release the target material into the carrier fluid, and flowing the carrier fluid out of the extractor.

29. The method of claim 25, wherein the target material comprises nucleic acid, a positive voltage is applied to the conductor while the sample flows through the extractor, and the nucleic acid is eluted by introducing a carrier fluid into the extractor, applying a negative voltage to the conductor to release the nucleic acid into the carrier fluid, and flowing the carrier fluid out of the extractor.

30. The method of claim 25, wherein the target material is eluted by removing the applied voltage and flowing a carrier fluid through the extractor.

31. The method of claim 25, wherein the underlying conductor comprises an array of structures, each of the structures having a height of at least 100 μ

m, and wherein the fluid sample is forced to flow between the structures as the voltage is applied.

32. The method of claim 25, wherein the underlying conductor comprises an array of columns, each of the columns having an aspect ratio (height to width or diameter) of at least 2:

1, and wherein the fluid sample is forced to flow between the columns as the voltage is applied.

33. The method of claim 25, wherein the insulator film is selected from the group consisting of silicon dioxide, silicon carbide, silicon nitride, and electrically insulating polymer.