Fluidics-based assay devices

• US 20040043507A1
• Filed: 08/27/2002
• Published: 03/04/2004
• Est. Priority Date: 08/27/2002
• Status: Active Grant

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Yang, Kaiyuan, Song, Xuedong, Kaylor, Rosann, Feaster, Shawn
• Granted Patent: US 7,314,763 B2
• Time in Patent Office: Days
• US Class Current: 436/514
• CPC Class Codes: B01L 2200/0668 Trapping microscopic beads
• CPC Class Codes: B01L 2300/0825 Test strips
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/043 magnetic forces
• CPC Class Codes: B01L 2400/0677 phase change valves; Meltable, freezing, dissolvable plugs; Destructible barriers
• 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: G01N 33/54333 Modification of conditions of immunological binding reaction, e.g. use of more than one type of particle, use of chemical agents to improve binding, choice of incubation time or application of magnetic field during binding reaction
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing
• CPC Class Codes: Y10S 435/969 Multiple layering of reactants
• CPC Class Codes: Y10S 435/97 Test strip or test slide
• CPC Class Codes: Y10T 436/10 Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing

Abstract

A fluidics-based assay device for detecting the presence or quantity of an analyte residing in a test sample is provided. The device utilizes a self-calibrated magnetic binding assay format (e.g., sandwich, competitive, etc.) that includes detection probes capable of generating a detection signal (e.g., fluorescent non-magnetic particles) and calibration probes capable of generating a calibration signal (e.g., fluorescent magnetic particles). The amount of the analyte within the test sample is proportional (e.g., directly or inversely) to the intensity of the detection signal calibrated by the intensity of the calibration signal. It has been discovered that the fluidics-based device of the present invention provides an accurate, inexpensive, and readily controllable method of determining the presence of an analyte in a test sample.

Claims

1. A fluidics-based assay device for detecting the presence or quantity of an analyte residing in a test sample, said device comprising:

a reaction chamber, said reaction chamber being capable of containing a solution that comprises the test sample, detection probes capable of generating a detection signal, and magnetic calibration probes capable of generating a calibration signal;

a channel in fluid communication with said reaction chamber, said channel defining a detection zone; and

a magnetic device positioned adjacent to said detection zone, said magnetic device being capable of separating said detection probes and said calibration probes from said solution;

wherein the amount of the analyte within the test sample is proportional to the intensity of the detection signal generated by said separated detection probes at the detection zone calibrated by the intensity of the calibration signal generated by said separated calibration probes at the detection zone.

2. A device as defined in claim 1, wherein said channel facilitates capillary flow of the test sample.

3. A device as defined in claim 1, further comprising a barrier disposed between said reaction chamber and said channel, said barrier being capable of holding said solution within said reaction chamber for a certain period of time.

4. A device as defined in claim 3, wherein said barrier is capable of being substantially dissolved by said solution.

5. A device as defined in claim 4, wherein said barrier contains a material selected from the group consisting of carbohydrates, salts, and combinations thereof.

6. A device as defined in claim 3, wherein said barrier is capable of physically rupturing after said certain period of time.

7. A device as defined in claim 1, wherein said detection probes and said calibration probes are fluorescent compounds, chemiluminescent compounds, phosphorescent compounds, or combinations thereof.

8. A device as defined in claim 1, wherein said detection probes are fluorescent non-magnetic compounds.

9. A device as defined in claim 1, wherein said calibration probes are fluorescent magnetic particles.

10. A device as defined in claim 1, wherein said detection probes are capable of binding to the analyte.

11. A device as defined in claim 1, further comprising non-fluorescent magnetic particles.

12. A device as defined in claim 11, wherein said non-fluorescent magnetic particles are capable of binding to the analyte.

13. A device as defined in claim 1, wherein said separated detection probes include complexes formed by said detection probes.

14. A device as defined in claim 1, wherein said separated calibration probes include complexes formed by said calibration probes.

15. A device as defined in claim 1, wherein the amount of the analyte within the test sample is proportional to the intensity of the detection signal generated by said separated detection probes at said detection zone divided by the intensity of the calibration signal generated by said separated calibration probes at said detection zone.

16. A capillary flow assay device for detecting the presence or quantity of an analyte residing in a test sample, said device comprising:

a reaction chamber, said reaction chamber being capable of containing a solution that comprises the test sample, detection probes capable of generating a detection signal, and magnetic calibration probes capable of generating a calibration signal;

a capillary channel in communication with said reaction chamber, said fluidic capillary channel defining a detection zone;

a barrier disposed between said reaction chamber and said capillary channel, said barrier being capable of holding said solution within said reaction chamber for a certain period of time; and

a magnetic device positioned adjacent to said detection zone, said magnetic device being capable of separating said detection probes and said calibration probes from said solution;

wherein the amount of the analyte within the test sample is proportional to the intensity of the detection signal generated by said separated detection probes at the detection zone calibrated by the intensity of the calibration signal generated by said separated calibration probes at the detection zone.

17. A device as defined in claim 16, wherein said barrier is capable of being substantially dissolved by said solution.

18. A device as defined in claim 17, wherein said barrier contains a material selected from the group consisting of carbohydrates, salts, and combinations thereof.

19. A device as defined in claim 16, wherein said barrier is capable of physically rupturing after said certain period of time.

20. A device as defined in claim 16, wherein said detection probes and said calibration probes are fluorescent compounds.

21. A device as defined in claim 16, wherein said detection probes are fluorescent non-magnetic compounds.

22. A device as defined in claim 16, wherein said calibration probes are fluorescent magnetic particles.

23. A device as defined in claim 16, wherein said separated detection probes include complexes formed by said detection probes.

24. A device as defined in claim 16, wherein said separated calibration probes include complexes formed by said calibration probes.

25. A device as defined in claim 16, wherein the amount of the analyte within the test sample is proportional to the intensity of the detection signal generated by said separated detection probes at said detection zone divided by the intensity of the calibration signal generated by said separated calibration probes at said detection zone.

26. A method for detecting the presence or quantity of an analyte residing in a test sample, said method comprising:

i) providing a fluidics-based device, said device comprising;

a) a reaction chamber containing detection probes capable of generating a detection signal and magnetic calibration probes capable of generating a calibration signal;

b) a channel in fluid communication with said reaction chamber that defines a detection zone; and

c) a magnetic device positioned adjacent to said detection zone;

ii) applying a test sample containing the analyte to the reaction chamber to form a solution;

iii) allowing said solution to flow from said reaction chamber to said detection zone of said channel;

iv) separating said detection probes and said calibration probes from said solution at said detection zone using said magnetic device;

v) exciting said separated detection probes and said separated calibration probes, wherein said excitation causes said separated detection probes to emit said detection signal and said separated calibration probes to emit said calibration signal;

vi) measuring the intensity of the detection signal at a first emission wavelength and the intensity of the calibration signal at a second emission wavelength; and

vii) comparing the intensity of the detection signal to the calibration signal, wherein the amount of the analyte within the test sample is proportional to the intensity of the detection signal calibrated by the intensity of the calibration signal.

27. A method as defined in claim 26, further comprising holding the solution within said reaction chamber for a certain period of time with a barrier that is disposed between said reaction chamber and said channel.

28. A method as defined in claim 26, wherein said detection and calibration probes are fluorescent.

29. A method as defined in claim 26, wherein said detection and calibration probes are chemiluminescent.

30. A method as defined in claim 26, wherein said detection and calibration probes are phosphorescent.

31. A method as defined in claim 26, wherein said detection probes are non-magnetic.

32. A method as defined in claim 26, wherein said separated detection probes include complexes formed by said detection probes.

33. A method as defined in claim 29, wherein said complexes are formed with the analyte.

34. A method as defined in claim 26, wherein said separated calibration probes include complexes formed by said calibration probes.

35. A method as defined in claim 31, wherein said complexes are formed with the analyte.

36. A method as defined in claim 26, wherein said first emission wavelength is different than said second emission wavelength.

37. A method as defined in claim 26, further comprising generating a calibration curve by plotting the intensity of the detection signal calibrated by the intensity of the calibration signal for a plurality of predetermined analyte concentrations.

38. A method as defined in claim 26, wherein said separated detection probes and said separated calibration probes are excited simultaneously.

39. A method as defined in claim 26, wherein said separated detection probes and said separated calibration probes are excited separately.

40. A method as defined in claim 26, wherein the intensity of the detection signal and the calibration signal are measured simultaneously.

41. A method as defined in claim 26, wherein the intensity of the detection signal and the calibration signal are measured separately.