Ratiometric Immunoassay Method and Blood Testing Device

• US 20120142025A1
• Filed: 12/01/2011
• Published: 06/07/2012
• Est. Priority Date: 12/03/2010
• Status: Active Grant

• Current Assignee: Abbott Point Of Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Point Of Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Miller, Cary James
• Granted Patent: US 9,052,309 B2
• Time in Patent Office: Days
• US Class Current: 435/7.9
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: B01L 3/50273 characterised by the means or forces applied to move the fluids micropumps F04B19/006, of the membrane type F04B43/043
• CPC Class Codes: G01N 2333/4737 C-reactive protein
• CPC Class Codes: G01N 2333/805 Haemoglobins; Myoglobins
• CPC Class Codes: G01N 33/54306 Solid-phase reaction mechanisms
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing
• CPC Class Codes: G01N 33/558 using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387
• CPC Class Codes: G01N 33/76 Human chorionic gonadotropin including luteinising hormone, follicle stimulating hormone, thyroid stimulating hormone or their receptors

Abstract

The invention is to devices and methods for rapid determination of analytes in liquid samples. The devices and methods incorporate a sample dilution feature and multiple immunosensors for performing a ratiometric immunoassay on a first analyte and a second analyte, for example, hemoglobin and hemoglobin A1c or albumin and glycosylated albumin. The devices are preferably capable of being used in the point-of-care diagnostic field.

Claims

1. A cartridge for performing a ratiometric assay in a blood sample, comprising:

a sample holding chamber oriented between a sample entry port and a sample isolation unit and having a diluent introduction port disposed therebetween for introduction of a diluent into the sample holding chamber, wherein the volume within the sample holding chamber between the diluent introduction port and the sample isolation unit defines a metered volume of a sample for analysis;

an analysis conduit in fluid communication with the sample isolation unit, the analysis conduit including a sensing region comprising a first sensor comprising an immunosensor for a first analyte, and a second sensor comprising an immunosensor for a second analyte; and

a pump for introducing the diluent from a diluent conduit into the sample holding chamber, and for moving said diluted sample into the sensing region.

2. The cartridge of claim 1, wherein the first sensor comprises an immobilized first antibody to the first analyte, and wherein the second sensor comprises an immobilized second antibody to the second analyte.

3. The cartridge of claim 1, further comprising a reagent coating comprises a mobile labeled antibody for binding to the first analyte and the second analyte.

4. The cartridge of claim 1, wherein the diluent that is introduced into the sample holding chamber comprises a metered volume of diluent.

5. The cartridge of claim 1, wherein the first analyte comprises hemoglobin and the second analyte comprises hemoglobin A1c.

6. The cartridge of claim 1, wherein the cartridge comprises a lysing agent capable of dissolving in the sample, the diluent, or the diluted sample.

7. The cartridge of claim 6, wherein said lysing agent comprises sodium deoxycholate.

8. The cartridge of claim 6, wherein said lysing agent comprises saponin.

9. The cartridge of claim 1, wherein the first analyte comprises albumin and the second analyte comprises glycosylated albumin.

10. The cartridge of claim 1, wherein said sample isolation unit comprises a capillary stop.

11. The cartridge of claim 1, wherein said sample isolation unit comprises a porous hydrophilic material.

12. The cartridge of claim 1, wherein said sample isolation unit comprises a cellulose material.

13. The cartridge of claim 1, wherein said sample isolation unit comprises nitrocellulose.

14. The cartridge of claim 1, wherein said sample isolation unit comprises cotton fiber.

15. The cartridge of claim 1, wherein said sample isolation unit comprises paper.

16. The cartridge of claim 1, wherein said sample isolation unit comprises glass-filled paper.

17. A method of performing a ratiometric assay in a blood sample, comprising:

introducing a blood sample through a sample entry port of a cartridge and into a sample holding chamber oriented between the sample entry port and a sample isolation unit and having a diluent introduction port disposed therebetween for introduction of a diluent into the sample holding chamber, wherein the volume within the sample holding chamber between the diluent introduction port and the sample isolation unit defines a metered volume of a sample for analysis;

pumping a diluent from a diluent conduit, through said diluent introduction port and into said sample holding chamber to form a diluted sample;

pumping said diluted sample to a sensing region comprising a first sensor and a second sensor, said first sensor comprising an immunosensor for a first analyte and said second sensor comprising an immunosensor for a second analyte;

forming a first sandwich on said first sensor comprising an immobilized first antibody, the first analyte and a first labeled antibody;

forming a second sandwich on said second sensor comprising an immobilized second antibody, the second analyte and a second labeled antibody;

washing said diluted sample from the sensing region;

generating a first signal from the first labeled antibody; and

generating a second signal from the second labeled antibody.

18. The method of claim 17, further comprising the step of determining the fractional percentage of the first analyte to the second analyte from the first and second signals.

19. The method of claim 17, wherein the blood sample is amended with an anticoagulant.

20. The method of claim 17, wherein said sample isolation unit comprises a capillary stop.

21. The method of claim 17, wherein said sample isolation unit comprises a porous hydrophilic material.

22. The method of claim 17, wherein said sample isolation unit comprises a cellulose material.

23. The method of claim 17, wherein said sample isolation unit comprises nitrocellulose.

24. The method of claim 17, wherein said sample isolation unit comprises cotton fiber.

25. The method of claim 17, wherein said sample isolation unit comprises paper.

26. The method of claim 17, wherein said sample isolation unit comprises glass-filled paper.

27. The method of claim 17, wherein the first analyte comprises hemoglobin and the second analyte comprises hemoglobin A1c.

28. The method of claim 17, wherein the cartridge comprises a lysing agent capable of dissolving in the sample, the diluent, or the diluted sample.

29. The method of claim 28, wherein said lysing agent comprises sodium deoxycholate.

30. The method of claim 28, wherein said lysing agent comprises saponin.

31. The method of claim 17, wherein the first analyte comprises albumin and the second analyte comprises glycosylated albumin.

32. The method of claim 17, wherein the metered volume of said sample is diluted to an analyte concentration range where the first sensor response is quasi-linear.

33. The method of claim 17, wherein the metered volume of said sample is diluted to an analyte concentration range where the second sensor response is quasi-linear.

34. The method of claim 17, wherein the diluted sample is at a dilution ratio of from 1:

1 to 50;

1 parts by volume diluent;

sample.

35. A cartridge for performing a ratiometric assay in a sample, comprising:

a sample holding chamber oriented between a sample entry port and a sample extraction unit, wherein a portion of said sample extraction unit is configured to define a metered volume of a sample;

an analysis conduit in fluid communication with the sample extraction unit, the analysis conduit including a sensing region comprising a first sensor comprising an immunosensor for a first analyte, and a second sensor comprising an immunosensor for a second analyte; and

a pump configured to transfer diluent through said diluent conduit, over and/or through said sample extraction unit, and into said analysis conduit.

36. The cartridge of claim 35, wherein the first sensor comprises an immobilized first antibody to the first analyte, and wherein the second sensor comprises an immobilized second antibody to the second analyte.

37. The cartridge of claim 35, further comprising a reagent coating comprises a mobile labeled antibody for binding to the first analyte and the second analyte.

38. The cartridge of claim 35, wherein the diluent that is introduced into the sample holding chamber comprises a metered volume of diluent.

39. The cartridge of claim 35, wherein the first analyte comprises hemoglobin and the second analyte comprises hemoglobin A1c.

40. The cartridge of claim 35, wherein the cartridge comprises a lysing agent capable of dissolving in the sample, the diluent, or the diluted sample.

41. The cartridge of claim 40, wherein said lysing agent comprises sodium deoxycholate.

42. The cartridge of claim 40, wherein said lysing agent comprises saponin.

43. The cartridge of claim 35, wherein the first analyte comprises albumin and the second analyte comprises glycosylated albumin.

44. The cartridge of claim 35, wherein said extraction unit comprises a porous hydrophilic material.

45. The cartridge of claim 35, wherein said extraction unit comprises a cellulose material.

46. The cartridge of claim 35, wherein said extraction unit comprises nitrocellulose.

47. The cartridge of claim 35, wherein said extraction unit comprises cotton fiber.

48. The cartridge of claim 35, wherein said extraction unit comprises paper.

49. The cartridge of claim 35, wherein said extraction unit comprises glass-filled paper.

50. The cartridge of claim 35, wherein said extraction unit comprises a transverse filter material.

51. The cartridge of claim 35, wherein said extraction unit comprises a porous outer coating.

52. A method of performing a ratiometric assay in a blood sample, comprising:

introducing a blood sample into a sample entry port of a cartridge and into a sample holding chamber oriented between said sample entry port and a sample extraction unit, wherein a distal portion of said extraction unit defines a metered volume of sample for dilution;

loading said extraction unit with said sample;

washing a portion of said sample from the sample extraction unit using a volume of diluent from a diluent conduit to form a diluted sample;

transferring said diluted sample to a sensing region comprising a first sensor and a second sensor, said first sensor comprising an immunosensor for a first analyte and said second sensor comprising an immunosensor for a second analyte;

forming a first sandwich on said first sensor comprising an immobilized first antibody, the first analyte and a first labeled antibody;

forming a second sandwich on said second sensor comprising an immobilized second antibody, the second analyte and a second labeled antibody;

washing said diluted sample from the sensing region;

generating a first signal from the first labeled antibody; and

generating a second signal from the second labeled antibody.

53. The method of claim 52, further comprising the step of determining the fractional percentage of the first analyte to the second analyte from the first and second signals.

54. The method of claim 52, wherein the blood sample is amended with an anticoagulant.

55. The method of claim 52, wherein said extraction unit comprises a porous hydrophilic material.

56. The method of claim 52, wherein said extraction unit comprises a cellulose material.

57. The method of claim 52, wherein said extraction unit comprises nitrocellulose.

58. The method of claim 52, wherein said extraction unit comprises cotton fiber.

59. The method of claim 52, wherein said extraction unit comprises paper.

60. The method of claim 52, wherein said extraction unit comprises glass-filled paper.

61. The method of claim 52, wherein said extraction unit comprises a transverse filter material.

62. The method of claim 52, wherein said extraction unit comprises a porous outer coating.

63. The method of claim 52, wherein the first analyte comprises hemoglobin and the second analyte comprises hemoglobin A1c.

64. The method of claim 52, wherein the cartridge comprises a lysing agent capable of dissolving in the sample, the diluent, or the diluted sample.

65. The method of claim 64, wherein said lysing agent comprises sodium deoxycholate.

66. The method of claim 64, wherein said lysing agent comprises saponin.

67. The method of claim 52, wherein the first analyte comprises albumin and the second analyte comprises glycosylated albumin.

68. The method of claim 52, wherein the metered volume of said sample is diluted to an analyte concentration range where the first sensor response is quasi-linear.

69. The method of claim 52, wherein the metered volume of said sample is diluted to an analyte concentration range where the second sensor response is quasi-linear.

70. The method of claim 52, wherein the diluted sample has a dilution ratio of from about 50:

1 to about 50,000;

1 (v/v diluent;

sample).