Lateral Flow and Flow-through Bioassay Devices Based On Patterned Porous Media, Methods of Making Same, and Methods of Using Same

• US 20090298191A1
• Filed: 04/16/2009
• Published: 12/03/2009
• Est. Priority Date: 10/18/2006
• Status: Active Grant

• Current Assignee: President and Fellows of Harvard College (Harvard Corporation)
• Original Assignee: President and Fellows of Harvard College (Harvard Corporation)
• Inventors: CARRILHO, Emanuel, LIU, Yanyan, WONG, Amy, SINDI, Hayat, THOMAS, Samuel W., MIRICA, Katherine A., PHILLIPS, Scott T., BUTTE, Manish J., MARTINEZ, Andres W., WHITESIDES, George M., VELLA, Sarah J.
• Granted Patent: US 8,377,710 B2
• Time in Patent Office: Days
• US Class Current: 436/164
• CPC Class Codes: B01L 2200/12 Specific details about manufacturing devices
• CPC Class Codes: B01L 2300/06 Auxiliary integrated devices, integrated components
• CPC Class Codes: B01L 2300/0848 Specific forms of parts of containers
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 2300/126 Paper
• CPC Class Codes: B01L 2300/161 Control and use of surface tension forces, e.g. hydrophobic, hydrophilic
• CPC Class Codes: B01L 3/502707 characterised by the manufacture of the container or its components by shaping or joining plastic parts B29C59/00, B29C65/00; by laminating B32B37/00; manufacture of microstructural devices in general B81C
• CPC Class Codes: B01L 3/502715 characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces
• CPC Class Codes: B01L 3/502761 specially adapted for handling suspended solids or molecules independently from the bulk fluid flow, e.g. for trapping or sorting beads, for physically stretching molecules investigating characteristics of particles G01N15/00
• CPC Class Codes: C12Q 1/48 involving transferase
• CPC Class Codes: G01N 21/77 by observing the effect on a chemical indicator
• CPC Class Codes: G01N 33/523 the element being adapted for a specific analyte
• CPC Class Codes: G01N 33/526 the element being adapted for a specific analyte
• CPC Class Codes: G01N 33/54388 based on lateral flow
• CPC Class Codes: G01N 33/54391 based on vertical flow
• CPC Class Codes: G01N 33/558 using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387
• CPC Class Codes: G06F 3/005 Input arrangements through a video camera

Abstract

Embodiments of the invention provide lateral flow and flow-through bioassay devices based on patterned porous media, methods of making same, and methods of using same. Under one aspect, an assay device includes a porous, hydrophilic medium; a fluid impervious barrier comprising polymerized photoresist, the barrier substantially permeating the thickness of the porous, hydrophilic medium and defining a boundary of an assay region within the porous, hydrophilic medium; and an assay reagent in the assay region.

Claims

1. An assay device, comprising:

a porous, hydrophilic medium;

a fluid impervious barrier comprising polymerized photoresist, the barrier substantially permeating the thickness of the porous, hydrophilic medium and defining a boundary of an assay region within the porous, hydrophilic medium; and

an assay reagent in the assay region.

2. The assay device of claim 1, wherein the barrier further defines a boundary of a channel region within the porous, hydrophilic medium, the channel region fluidically connected to the assay region.

3. The assay device of claim 2, wherein the barrier further defines a boundary of a sample deposition region within the porous, hydrophilic medium, the channel providing a fluidic pathway within the porous, hydrophilic medium between the sample deposition region and the assay region.

4. The assay device of claim 1, wherein the barrier further defines boundaries of a plurality of assay regions.

5. The assay device of claim 4, wherein the barrier further defines boundaries of a plurality of channel regions within the porous, hydrophilic medium and further defines a boundary of a sample deposition region, each channel providing a fluidic pathway within the porous, hydrophilic medium between the sample deposition region and a corresponding assay region of the plurality of assay regions.

6. The assay device of claim 4, further comprising assay reagents in at least some of the assay regions.

7. The assay device of claim 4, wherein the barrier physically separates the assay regions of the plurality of assay regions from one another.

8. The assay device of claim 1, wherein the assay reagent is covalently bonded to the porous, hydrophilic medium in the assay region.

9. The assay device of claim 1, wherein the assay reagent is noncovalently bonded to the porous, hydrophilic medium in the assay region.

10. The assay device of claim 1, wherein the assay reagent is selected to provide a visible indication of the presence of analyte.

11. The assay device of claim 1, wherein the assay reagent is selected to react to the presence of at least one of glucose, protein, fat, vascular endothelial growth factor, insulin-like growth factor 1, antibodies, and cytokines.

12. The assay device of claim 1, wherein the photoresist comprises negative photoresist.

13. The assay device of claim 1, wherein the porous, hydrophilic medium comprises one of nitrocellulose acetate, cellulose acetate, cellulosic paper, filter paper, tissue paper, writing paper, paper towel, cloth, and porous polymer film.

14. The assay device of claim 1, wherein the porous, hydrophilic medium is flexible.

15. The assay device of claim 1, wherein the barrier has at least one dimension between about 5 cm and about 100 μ

m.

16. The assay device of claim 1, wherein the barrier has at least one dimension between about 300 μ

m and about 100 μ

m.

17. The assay device of claim 1, wherein the barrier has at least one dimension less than about 300 μ

m.

18. The assay device of claim 2, wherein the channel has at least one lateral dimension that is between about 750 μ

m and about 100 μ

m.

19. The assay device of claim 2, wherein the channel has at least one lateral dimension that is between about 250 μ

m and about 100 μ

m.

20. The assay device of claim 2, wherein the channel has at least one lateral dimension that is less than about 250 μ

m.

21. The assay device of claim 1, further comprising an imaging device capable of obtaining a digital image of the assay region.

22. The assay device of claim 21, further comprising a processor in communication with the imaging device and capable of obtaining information about an analyte in the assay region based on the digital image of the assay region.

23. The assay device of claim 22, wherein the processor is capable of obtaining the information about the analyte based on an intensity in the digital image of the assay region.

24. The assay device of claim 1, further comprising a layer over the porous hydrophilic medium, the layer including at least one aperture.

25. The assay device of claim 24, wherein the aperture provides at least part of a fluidic pathway to the assay region.

26. An assay device, comprising:

a porous, hydrophilic medium;

a fluid impervious barrier substantially permeating the thickness of the porous, hydrophilic medium and having a width between about 1 mm and about 100 μ

m, the barrier completely defining a boundary of an assay region within the porous, hydrophilic medium; and

an assay reagent in the assay region.

27. The assay device of claim 26, wherein the assay reagent is selected to provide a visible indication of the presence of analyte.

28. The assay device of claim 26, wherein the assay reagent is selected to react to the presence of at least one of glucose, protein, fat, vascular endothelial growth factor, insulin-like growth factor 1, antibodies, and cytokines.

29. The assay device of claim 26, wherein the barrier comprises one of photoresist and curable polymer.

30. The assay device of claim 26, wherein the porous, hydrophilic medium comprises one of nitrocellulose acetate, cellulose acetate, cellulosic paper, filter paper, tissue paper, writing paper, paper towel, cloth, and porous polymer film.

31. The assay device of claim 26, wherein the barrier has at least one lateral dimension between about 300 μ

m and about 100 μ

m.

32. The assay device of claim 26, wherein the barrier has at least one lateral dimension less than about 300 μ

m.

33. The assay device of claim 26, further comprising a plurality of fluid impervious barriers substantially permeating the thickness of the porous, hydrophilic medium, each barrier having a width between about 1 mm and about 100 μ

m, each barrier each completely defining a boundary of a corresponding assay region within the porous, hydrophilic medium; and

an assay reagent in each assay region.

34. An assay device, comprising:

a porous, hydrophilic medium;

a fluid impervious barrier substantially permeating the thickness of the porous, hydrophilic medium and having a length and a width that varies by less than about 10% along the length of the barrier, the barrier defining a boundary of an assay region within the porous, hydrophilic medium, and

an assay reagent in the assay region.

35. The assay device of claim 34, wherein the barrier further defines a boundary of a channel region within the porous, hydrophilic medium, the channel region fluidically connected to the assay region.

36. The assay device of claim 35, wherein the barrier further defines a boundary of a sample deposition region within the porous, hydrophilic medium, the channel providing a fluidic pathway within the porous, hydrophilic medium between the sample deposition region and the assay region.

37. The assay device of claim 34, wherein the assay reagent is selected to provide a visible indication of the presence of analyte.

38. The assay device of claim 34, wherein the assay reagent is selected to react to the presence of one of glucose, protein, fat, vascular endothelial growth factor, insulin-like growth factor 1, antibodies, and cytokines.

39. The assay device of claim 34, wherein the barrier comprises one of photoresist and curable polymer.

40. The assay device of claim 34, wherein the porous, hydrophilic medium comprises one of nitrocellulose acetate, cellulose acetate, cellulosic paper, filter paper, tissue paper, writing paper, paper towel, cloth, and porous polymer film.

41. The assay device of claim 34, wherein the barrier width is less than about 300 μ

m.

42. The assay device of claim 34, wherein the barrier width varies by less than about 5% along the length of the barrier.

43. The assay device of claim 35, wherein the channel region has at a width between about 750 μ

m and about 100 μ

m.

44. The assay device of claim 35, wherein the channel region has a length and a width that varies by less than about 10% along the length of the channel.

45. The assay device of claim 35, wherein the channel region has a length and a width that varies by less than about 5% along the length of the channel.

46. A method of making a device, the method comprising:

saturating a porous, hydrophilic medium with photoresist;

exposing the saturated medium to a pre-determined pattern of light;

removing the photoresist from a region of the medium based on the pre-determined pattern of light to define a barrier of residual photoresist that forms a boundary of the region, wherein the pre-determined pattern of light is selected so that the barrier defines an assay region in the region; and

providing an assay reagent in the assay region.

47. The method of claim 46, wherein the barrier is substantially fluid impervious.

48. The method of claim 46, comprising selecting the pre-determined pattern of light so that the barrier completely encompasses the region.

49. The method of claim 46, comprising selecting the pre-determined pattern of light so that the barrier borders a first portion of the region, and wherein an edge of the porous, hydrophilic medium borders a second portion of the region.

50. The method of claim 46, wherein providing the reagent comprises covalently binding the reagent to the assay region.

51. The method of claim 46, wherein providing the reagent comprises noncovalently binding the reagent to the assay region.

52. The method of claim 46, comprising selecting wherein the pre-determined pattern of light so that the assay region has a shape based on transport characteristics of the reagent in the presence of a liquid.

53. The method of claim 46, wherein the reagent is selected to provide a visible indication of the presence of analyte.

54. The method of claim 46, wherein the assay reagent is selected to react to the presence of one of glucose, protein, fat, vascular endothelial growth factor, insulin-like growth factor 1, antibodies, and cytokines.

55. The method of claim 46, comprising selecting the pre-determined pattern of light so that the barrier defines a channel region in the region.

56. The method of claim 46, wherein the channel region has at least one lateral dimension that is between about 750 μ

m and about 100 μ

m.

57. The method of claim 46, comprising selecting the pre-determined pattern of light is selected so that the barrier defines a sample deposition region in the region.

58. The method of claim 46, wherein the saturating the porous, hydrophilic medium with photoresist comprises applying a solution of the photoresist in a solvent to the medium and substantially evaporating the solvent.

59. The method of claim 46, wherein exposing the saturated medium to a pre-determined pattern of light comprises irradiating the region with the light and substantially not irradiating the barrier with the light.

60. The method of claim 46, wherein exposing the saturated medium to a pre-determined pattern of light comprises irradiating the barrier with the light and substantially not irradiating the region with the light.

61. The method of claim 46, wherein removing the photoresist comprises removing the photoresist from a plurality of regions of the medium based on the pre-determined pattern of light to define a plurality of barriers of residual photoresist that form boundaries of corresponding regions.

62. The method of claim 46, further comprising:

saturating a second porous, hydrophilic medium with photoresist;

exposing the saturated second medium to a pre-determined pattern of light;

removing the photoresist from a region of the second medium based on the pre-determined pattern of light to define a barrier of residual photoresist that forms a boundary of the region;

substantially aligning the barrier of the second medium with the barrier of the first mentioned medium; and

bonding the first medium to the second medium.

63. The method of claim 62, comprising applying a reagent in the region of the first medium, the reagent selected to react to a target analyte.

64. The method of claim 63, further comprising providing one of a labeled antibody and a labeled protein in the region of the second medium, the one of the labeled antibody and the labeled protein selected to provide a color indication of a reaction between the reagent and the target analyte.

65. The method of claim 46, further comprising providing a layer over the porous, hydrophilic medium, the layer including at least one aperture that is aligned based on a position of the barrier.

66. The method of claim 46, comprising selecting the pre-determined pattern of light so that the barrier has at least one dimension that is between about 5 cm and about 100 μ

m.

67. The method of claim 46, comprising selecting the pre-determined pattern of light so that the barrier has at least one dimension that is less than about 250 μ

m.

68. The method of claim 46, wherein the porous, hydrophilic medium comprises one of nitrocellulose acetate, cellulose acetate, cellulosic paper, filter paper, tissue paper, writing paper, paper towel, cloth, and porous polymer film.

69. The method of claim 46, further comprising:

removing the photoresist from a plurality of regions of the medium based on the pre-determined pattern of light to define a plurality of barriers of residual photoresist that form boundaries of a corresponding plurality of regions, wherein the pre-determined pattern of light is selected so that the plurality of barriers define a corresponding plurality of assay regions in the regions; and

providing an assay reagent in at least some of the assay regions.

70. A method of making a device, the method comprising:

coating a stamp of pre-determined pattern with a curable polymer;

pressing the coated stamp onto a porous, hydrophilic medium, the medium having a thickness and the curable polymer substantially permeating the medium through its thickness in accordance with the pre-determined pattern;

curing the curable polymer so as to form a fluid impervious barrier embedded in the medium, the fluid impervious barrier defining an assay region in the medium; and

providing a reagent in the assay region.

71. The method of claim 70, wherein the curable polymer comprises poly(dimethyl-siloxane) (PDMS).

72. The method of claim 70, comprising selecting the pre-determined pattern so that the barrier completely encompasses the region.

73. A method of performing an assay to determine the presence of an analyte in a liquid sample, the method comprising:

depositing the liquid sample on an assay device, the assay device comprising a porous, hydrophilic medium, a fluid impervious barrier comprising polymerized photoresist, the barrier substantially permeating the thickness of the porous, hydrophilic medium and defining a boundary of an assay region within the porous, hydrophilic medium, and an assay reagent in the assay region, the assay reagent selected to provide a visible response to the presence of the analyte;

obtaining an image of the assay region; and

determining the presence of the analyte in the liquid based on the image of the assay region.

74. The method of claim 73, wherein determining the presence of the analyte in the liquid comprises obtaining an average intensity of at least a portion of the image of the assay region, and determining the presence of the analyte in the liquid based on the average intensity.

75. The method of claim 73, wherein obtaining the image of the assay region comprises imaging the assay region with one of a camera phone, a digital camera, and a scanner.

76. The method of claim 73, wherein determining the presence of the analyte based on the image of the assay region comprises transmitting the image to a remote lab, and obtaining information from the remote lab regarding the presence of the analyte in the liquid.

77. The method of claim 73, wherein obtaining the image of the assay region comprises imaging the assay region with a camera phone, and wherein determining the presence of the analyte based on the image of the assay region comprises transmitting the image to a remote lab via the camera phone.

78. A three-dimensional microfluidic device comprising:

a plurality of patterned porous, hydrophilic layers, wherein each said patterned porous, hydrophilic layer comprises a fluid-impermeable barrier that substantially permeates the thickness of said patterned porous, hydrophilic layer and defines a boundary of one or more hydrophilic regions within each said patterned porous, hydrophilic layer; and

a fluid-impermeable layer disposed between every two adjacent said patterned porous, hydrophilic layers, wherein said fluid-impermeable layer comprises one or more openings, said openings in flow communication with at least one hydrophilic region in at least one patterned porous, hydrophobic layer.

79. The three-dimensional microfluidic device of claim 78, wherein said porous, hydrophilic layer is selected from the group consisting of nitrocellulose acetate, cellulose acetate, cellulosic paper, filter paper, tissue paper, writing paper, paper towel, cloth, and porous polymer film.

80. The three-dimensional microfluidic device of claim 78, wherein said porous, hydrophilic layer comprises chromatography paper.

81. The three-dimensional microfluidic device of claim 78, wherein said barrier comprises photoresist.

82. The three-dimensional microfluidic device of claim 78, wherein said fluid-impermeable layer comprises a plastic sheet.

83. The three-dimensional microfluidic device of claim 82, wherein said plastic sheet comprises adhesive tape.

84. The three-dimensional microfluidic device of claim 83, wherein said adhesive tape comprises double-sided adhesive tape.

85. The three-dimensional microfluidic device of claim 78, wherein said hydrophilic regions comprise:

a first hydrophilic region comprising a reservoir for receiving a first fluid;

a second hydrophilic region comprising one or more distributing regions for receiving said first fluid from said reservoir; and

a plurality of hydrophilic regions for receiving said first fluid from said distributing region(s).

86. The three-dimensional microfluidic device of claim 85,

wherein each hydrophilic region of said plurality of hydrophilic regions further comprises an assaying reagent for assaying said first fluid.