Diffusion mediated clean-up of a target carrier fluid

• US 20070042406A1
• Filed: 07/13/2006
• Published: 02/22/2007
• Est. Priority Date: 07/18/2005
• Status: Abandoned Application

• Current Assignee: U.S. Genomics, Inc (Toxic Reports LLC)
• Original Assignee: U.S. Genomics, Inc (Toxic Reports LLC)
• Inventors: Larson, Jonathan, Gilmanshin, Rudolf, Yantz, Gregory
• Application Number:
  US11/486,446
• Publication Number:
  US 20070042406A1
• Time in Patent Office: Days
• US Class Current: 435/6
• CPC Class Codes: B01L 2200/0636 Focussing flows, e.g. to laminate flows
• CPC Class Codes: B01L 2300/0864 comprising only one inlet and multiple receiving wells, e.g. for separation, splitting
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 3/502776 specially adapted for focusing or laminating flows
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 5/00 Nanobiotechnology or nanomedicine, e.g. protein engineering or drug delivery

Abstract

Microfludic channels are constructed for use in preparing and/or analyzing samples. In one embodiment, a microfluidic channel receives a carrier fluid having both non-targets and targets. The non-targets are moved from the carrier fluid by diffusion and into sheathing fluids also present in the channel before contents of the carrier fluid are analyzed.

Claims

1. A microfluidic apparatus comprising:

a microchannel having an upstream portion and a downstream portion, the microchannel constructed and arranged to transport a carrier fluid such that, when present in the carrier fluid, targets and non-targets flow from the upstream portion toward the downstream portion;

a first sheathing fluid introduction channel adapted to provide a first sheathing fluid to the microchannel such that non-targets can diffuse from the carrier fluid to the first sheathing fluid; and

a sample capture channel located downstream from the first sheathing fluid introduction channel and adapted to receive the carrier fluid after at least a portion of the non-targets have diffused from the carrier fluid and into the first sheathing fluid.

2-36. -36. (canceled)

37. A method of removing non-targets from a carrier fluid that contains targets, the method comprising:

providing a microchannel adapted to deliver the carrier fluid from an upstream portion toward a downstream portion of the microchannel;

providing the carrier fluid to the upstream portion of the microchannel, the carrier fluid containing a plurality of targets and a plurality of non-targets;

providing a first sheathing fluid to the microchannel such that the first sheathing fluid flows from the upstream portion toward the downstream portion adjacent to the carrier fluid;

diffusing a first portion of the plurality of non-targets from the carrier fluid to the first sheathing fluid; and

passing the carrier fluid through a sample capture channel after the first portion of the targets have diffused from the carrier fluid and into the first sheathing fluid.

38. The method of claim 37, wherein the sample capture channel is constructed and arranged and conditions are such that the first portion is at least 60% (0.60) of the plurality of non-targets provided to the microchannel.

39. The method of claim 37, wherein the sample capture channel is constructed and arranged and conditions are such that the first portion is at least 85% (0.85) of the plurality of non-targets provided to the microchannel.

40. The method of claim 37, further comprising:

retaining within the carrier fluid at least 80% (0.80) of the plurality of targets provided to the microchannel as the carrier fluid is passed through the sample capture channel.

41. The method of claim 37, further comprising:

retaining within the carrier fluid at least 90% (0.90) of the plurality of targets provided to the microchannel as the carrier fluid is passed through the sample capture channel.

42. The method of claim 37, wherein providing the first sheathing fluid comprises providing a pair of opposed flows of sheathing fluid to the microchannel.

43. The method of claim 42, further comprising:

creating a velocity gradient within the carrier fluid with the pair of opposed flows of sheathing fluid.

44. The method of claim 37, further comprising:

removing at least a portion of the first sheathing fluid from the microchannel such that the first portion of non-targets contained therein is removed from the microchannel.

45. The method of claim 37, wherein removing at least a portion of the first sheathing fluid comprises removing substantially all of the first sheathing fluid.

46. The method of claim 37, wherein removing at least a portion of the first sheathing fluid comprises removing a portion of the carrier fluid.

47. The method of claim 37, further comprising:

providing a second sheathing fluid to the microchannel;

diffusing a second portion of the plurality of non-targets diffuse from the carrier fluid to the second sheathing fluid; and

passing the carrier fluid through a second sample capture channel after the second portion of the targets have diffused from the carrier fluid and into the second sheathing fluid.

48. The method of claim 47, wherein the second sample capture channel is constructed and arranged such that the carrier fluid passed through the second sample capture channel contains fewer than 90% (0.90) of the non-targets provided to the microchannel after the second portion of non-targets has diffused to the second sheathing fluid.

49. The method of claim 47, wherein the second sample capture channel is constructed and arranged such that the carrier fluid passed through the second sample capture channel contains fewer than 95% (0.95) of the non-targets provided to the microchannel after the second portion of non-targets has diffused to the second sheathing fluid.

50. The method of claim 47, wherein the second sample capture channel is constructed and arranged such that the carrier fluid passed through the second sample capture channel contains more than 80% (0.80) of the targets provided to the microchannel.

51. The method of claim 47, wherein the second sample capture channel is constructed and arranged such that the carrier fluid passed through the second sample capture channel contains more than 90% of the targets provided to the microchannel.

52. The method of claim 47, further comprising:

removing at least a portion of the second sheathing fluid from the microchannel such that non-targets contained therein are removed from the microchannel; and

then providing a third sheathing fluid to the microchannel such that at least a third portion of the plurality of non-targets diffuse from the carrier fluid to the third sheathing fluid.

53. The method of claim 37, wherein the carrier fluid moves in the microchannel with a velocity between 0.1 and 20.0 mm/second.

54. The method of claim 37, wherein the plurality of targets include polymers.

57. The method of claim 37, wherein the plurality of targets include nucleic acids.

55-56. -56. (canceled)

58-67. -67. (canceled)