Assay Devices with Integrated Sample Dilution and Dilution Verification and Methods of Using Same

• US 20120142026A1
• 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, Davis, Graham, Zelin, Michael
• Granted Patent: US 9,050,595 B2
• Time in Patent Office: Days
• US Class Current: 435/7.9
• CPC Class Codes: B01F 31/65 the materials to be mixed being directly submitted to a pulsating movement, e.g. by means of an oscillating piston or air column
• CPC Class Codes: B01L 2200/10 Integrating sample preparation and analysis in single entity, e.g. lab-on-a-chip concept
• CPC Class Codes: B01L 2200/16 Reagents, handling or storing thereof
• CPC Class Codes: B01L 2300/045 whereby the whole cover is slidable
• CPC Class Codes: B01L 2300/0645 Electrodes
• CPC Class Codes: B01L 2300/0672 Integrated piercing tool
• 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 2300/0867 Multiple inlets and one sample wells, e.g. mixing, dilution
• CPC Class Codes: B01L 2300/126 Paper
• CPC Class Codes: B01L 2400/0481 squeezing of channels or chambers
• CPC Class Codes: B01L 2400/0672 Swellable plugs
• CPC Class Codes: B01L 3/502 with fluid transport, e.g. in multi-compartment structures centrifugal-type cuvettes G01N21/07; analysis by separation into components G01N30/00; automatic analysers G01N35/00
• 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 21/25 Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
• CPC Class Codes: G01N 21/78 producing a change of colour
• CPC Class Codes: G01N 27/02 by investigating impedance
• CPC Class Codes: G01N 27/26 by investigating electrochemical variables; by using electrolysis or electrophoresis
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52
• CPC Class Codes: G01N 27/3274 : Corrective measures, e.g. error detection, compensation for temperature or hematocrit, calibration coding of calibration information G01N33/48771
• CPC Class Codes: G01N 27/413 : Concentration cells using liquid electrolytes measuring currents or voltages in voltaic cells
• CPC Class Codes: G01N 27/49 : Systems involving the determination of the current at a single specific value, or small range of values, of applied voltage for producing selective measurement of one or more particular ionic species
• CPC Class Codes: G01N 33/54366 : Apparatus specially adapted for solid-phase testing
• CPC Class Codes: G01N 33/54373 : involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings
• 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 method for rapid determination of analytes in liquid samples by various assays including immunoassays incorporating a sample dilution feature for forming a diluted sample for analysis. The devices and methods also include a dilution verification feature for verifying the degree of dilution of the diluted sample. The devices preferably are capable of being used in the point-of-care diagnostic field is provided.

Claims

1. A method of performing an assay for an analyte in a fluid sample with a cartridge having an integrated sample dilution element, where the cartridge is adapted for insertion into a reading apparatus, the method comprising:

(a) introducing a fluid sample into a sample holding chamber of a cartridge with a sample dilution element, wherein at least a portion of said dilution element determines a volume of sample for dilution, and wherein said dilution element further comprises a predetermined known amount of a dilution determinant marker capable of dissolving into said sample;

(b) pumping a metered volume of diluent from a diluent chamber in said cartridge, to said sample dilution element to form a diluted sample;

(c) pumping the diluted sample to a sensor in a sensing region of said cartridge;

(d) measuring the concentration of said dilution determinant marker in said diluted sample; and

(e) determining the dilution ratio of the diluted sample from said measured concentration in step (d) and said predetermined known amount of step (a).

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

1 to 50;

1 parts by volume diluent;

sample.

3. The method of claim 1, wherein the diluted sample is at a dilution ratio of from 50:

1 to about 50,000;

1 parts by volume diluent;

sample.

4. The method of claim 1, wherein said dilution determinant marker is selected from the group consisting of an electrochemical species, ferricyanide, ruthenium hexamine, a ferrocene, ferrocene monocarboxylic acid, an optical dye, fluorescein, an acridinium salt, and methylene blue.

5. The method of claim 1, wherein the dilution determinant marker concentration is measured using an electrochemical analysis system for amperometric measurements.

6. The method of claim 1, wherein the dilution determinant marker concentration is measured using a potentiometric sensor.

7. The method of claim 1, wherein the dilution determinant marker concentration is measured using a spectrophotometer.

8. The method of claim 1, wherein the predetermined known amount of dilution determinant marker is an embedded value in said reading apparatus.

9. The method of claim 1, wherein the predetermined known amount of dilution determinant marker is an embedded value on said assay cartridge and automatically read by said reading apparatus.

10. The method of claim 1, wherein the predetermined known amount of dilution determinant marker is a visible value on said assay cartridge and manually entered into said reading apparatus.

11. The method of claim 1, wherein the predetermined known amount of dilution determinant marker is a visible value on said assay cartridge package and manually entered into said reading apparatus.

12. The method of claim 1, wherein the dilution ratio value determined in step (e) is used to calculate the concentration of the analyte in the undiluted sample.

13. A sensor cartridge for sensing at least one analyte in a sample, comprising:

at least one sensor in an analysis conduit;

a sample chamber between a sample entry port and a sample extraction unit, wherein said extraction unit comprises a dilution determinant marker;

a diluent package containing a diluent;

a diluent conduit configured for transporting diluent from the diluent package to the sample extraction unit; and

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

14. The sensor cartridge of claim 13, wherein said extraction unit comprises a dilution determinant marker selected from the group consisting of an electrochemical species, ferricyanide, ruthenium hexamine, a ferrocene, ferrocene monocarboxylic acid, an optical dye, fluorescein, an acridinium salt, and methylene blue.

15. The sensor cartridge of claim 13, wherein said diluent conduit defines a metered volume of diluent.

16. The sensor cartridge of claim 13, wherein said cartridge has opposing surfaces that are folded together.

17. The sensor cartridge of claim 13, wherein said cartridge is a single-use cartridge.

18. The sensor cartridge of claim 13, wherein said sensor is an immunosensor.

19. The sensor cartridge of claim 13, wherein said sensor is selected from the group consisting of an ion sensor, a metabolite sensor, an enzymatic sensor, an enzyme activity sensor and a nucleotide sensor.

20. The sensor cartridge of claim 13, wherein said cartridge is configured to dilute said sample at a dilution ratio of about 50:

1 to about 50,000;

1 parts by volume diluent;

sample.

21. A method of performing an assay for an analyte in a sample, said method comprising the steps of:

introducing a sample into a sample chamber of a cartridge, wherein the sample chamber terminates in a sample extraction unit comprising a dilution determinant marker;

loading said extraction unit with said sample;

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

measuring the amount of dilution determinant marker in said diluted sample; and

analyzing said diluted sample for an analyte.

22. The method of claim 21, further comprising calculating a dilution ratio of said diluted sample.

23. The method of claim 21, wherein said dilution determinant marker comprises an electrochemical species.

24. The method of claim 21, wherein said dilution determinant marker comprises ferricyanide.

25. The method of claim 21, wherein said dilution determinant marker comprises ruthenium hexamine.

26. The method of claim 21, wherein said dilution determinant marker comprises a ferrocene.

27. The method of claim 21, wherein said dilution determinant marker comprises an optical dye.

28. The method of claim 21, wherein said dilution determinant marker comprises fluorescein.

29. The method of claim 21, wherein said dilution determinant marker comprises an acridinium salt.

30. The method of claim 21, wherein said dilution determinant marker comprises methylene blue.

31. The method of claim 21, wherein the dilution determinant marker concentration is measured using an electrochemical analysis system for amperometric measurements.

32. The method of claim 21, wherein the dilution determinant marker concentration is measured using a potentiometric sensor.

33. The method of claim 21, wherein the dilution determinant marker concentration is measured using a spectrophotometer.

34. A method of performing an assay for an analyte in a sample, said method comprising the steps of:

adding a dilution determinant marker to the sample;

determining the dilution determinant marker concentration in the sample;

introducing the sample into a sample chamber of a cartridge, wherein the sample chamber terminates in a sample extraction unit;

loading said extraction unit with said sample;

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

measuring the dilution determinant marker concentration in said diluted sample;

comparing the dilution determinant marker concentration in the sample prior to introducing said sample into the sample chamber with the dilution determinant marker concentration in the portion of the sample washed from the extraction unit; and

analyzing said diluted sample for an analyte.

35. The method of claim 34, wherein said dilution determinant marker is selected from the group consisting of an electrochemical species, ferricyanide, ruthenium hexamine, a ferrocene, ferrocene monocarboxylic acid, an optical dye, fluorescein, an acridinium salt, and methylene blue.

36. The method of claim 34, wherein the dilution determinant marker concentration is measured using an electrochemical analysis system for amperometric measurements.

37. The method of claim 34, wherein the dilution determinant marker concentration is measured using a potentiometric sensor.

38. The method of claim 34, wherein the dilution determinant marker concentration is measured using a spectrophotometer.

39. A method of performing an assay for an analyte in a sample, said method comprising the steps of:

introducing a sample into a sample chamber of a cartridge, wherein the sample chamber terminates in a sample extraction unit;

loading said extraction unit with said sample;

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

analyzing said diluted sample for an analyte; and

characterizing a dilution ratio of the diluted sample.

40. The method of claim 39, wherein said extraction unit comprises a dilution determinant marker, which is used in characterizing the dilution ratio.

41. The method of claim 40, wherein said dilution determinant marker is selected from the group consisting of an electrochemical species, ferricyanide, ruthenium hexamine, a ferrocene, ferrocene monocarboxylic acid, an optical dye, fluorescein, an acridinium salt, and methylene blue.

42. The method of claim 40, wherein the dilution determinant marker concentration is measured using an electrochemical analysis system for amperometric measurements.

43. The method of claim 40, wherein the dilution determinant marker concentration is measured using a potentiometric sensor.

44. The method of claim 40, wherein the dilution determinant marker concentration is measured using a spectrophotometer.

45. The method of claim 39, wherein the volume of diluent is a metered volume of diluent.

46. The method of claim 39, further comprising:

transporting said diluted sample to a sensor; and

performing an analyte assay at said sensor.

47. The method of claim 39, wherein the sample is diluted in the range of about 50:

1 to about 50,000;

1 parts by volume diluent;

sample.

48. A method of performing an assay for an analyte in a sample, said method comprising the steps of:

introducing a sample into a sample chamber of a cartridge, wherein said chamber is located between a sample entry port and a sample isolation unit and includes a diluent introduction port for receiving diluent, and wherein the volume between the diluent introduction port and the sample isolation unit defines a metered volume of said sample for dilution;

transporting a volume of diluent from a diluent conduit to the metered volume of sample, wherein said volume of diluent is combined with said metered volume of sample to form a diluted sample;

transporting said diluted sample to a sensor;

performing an analyte assay at said sensor; and

characterizing a dilution ratio of the diluted sample.

49. The method of claim 48, further comprising adding a dilution determinant marker to said sample, wherein said dilution ratio is characterized using the dilution determinant marker.

50. The method of claim 49, wherein said dilution determinant marker is selected from the group consisting of an electrochemical species, ferricyanide, ruthenium hexamine, a ferrocene, ferrocene monocarboxylic acid, an optical dye, fluorescein, an acridinium salt, and methylene blue.

51. The method of claim 49, wherein the dilution determinant marker concentration is measured using an electrochemical analysis system for amperometric measurements.

52. The method of claim 49, wherein the dilution determinant marker concentration is measured using a potentiometric sensor.

53. The method of claim 49, wherein the dilution determinant marker concentration is measured using a spectrophotometer.

54. The method of claim 48, wherein the at least one analyte for sensing is CRP.

55. The method of claim 48, wherein the volume of diluent comprises a metered volume of diluent.

56. The method of claim 55, wherein the cartridge includes a pump conduit beginning at a pump and ending at an air introduction port on the diluent conduit, and wherein a region in the diluent conduit between the air introduction port and the diluent introduction port defines the metered volume of diluent.

57. The method of claim 48, wherein the sample is selected from the group consisting of blood, plasma, serum, urine, interstitial fluid and cerebrospinal fluid.

58. The method of claim 48, wherein said sample isolation unit comprises a capillary stop.

59. The method of claim 48, wherein said sample isolation unit is selected from the group consisting of a porous hydrophilic material, a cellulose material, nitrocellulose, cotton fiber, paper, and glass-filled paper.

60. The method of claim 48, wherein the diluted sample is at a dilution ratio of from 1:

1 to 50;

1 parts by volume diluent;

sample.