Self-encoding sensor with microspheres

• US 20050196317A1
• Filed: 01/21/2005
• Published: 09/08/2005
• Est. Priority Date: 10/06/1997
• Status: Active Grant

• Current Assignee: Tufts University
• Original Assignee: Trustees of Tufts College
• Inventors: Walt, David R., Dickinson, Todd A.
• Granted Patent: US 7,754,498 B2
• Time in Patent Office: Days
• US Class Current: 422/400
• CPC Class Codes: B01J 2219/00317 Microwell devices, i.e. having large numbers of wells
• CPC Class Codes: B01J 2219/0045 using optical fibres
• CPC Class Codes: B01J 2219/00466 in a slurry
• CPC Class Codes: B01J 2219/005 Beads
• CPC Class Codes: B01J 2219/00524 in the shape of fiber bundles
• CPC Class Codes: B01J 2219/00585 Parallel processes
• CPC Class Codes: B01J 2219/00648 by the use of solid beads
• CPC Class Codes: B01J 2219/00659 Two-dimensional arrays
• CPC Class Codes: C12Q 1/682 Signal amplification
• CPC Class Codes: C12Q 1/6834 Enzymatic or biochemical coupling of nucleic acids to a solid phase
• CPC Class Codes: C40B 60/14 for creating libraries
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 21/6452 Individual samples arranged in a regular 2D-array, e.g. multiwell plates
• CPC Class Codes: G01N 21/7703 using reagent-clad optical fibres or optical waveguides using measurement of total internal reflection or attenuated total reflection G01N21/552; optical fibres or waveguides per se G02B
• CPC Class Codes: G01N 2201/0846 Fibre interface with sample, e.g. for spatial resolution
• CPC Class Codes: G01N 33/0031 comprising two or more sensors, e.g. a sensor array electrochemical electrode arrays G01N27/27
• CPC Class Codes: G01N 33/54313 the carrier being characterised by its particulate form
• CPC Class Codes: Y10T 436/101666 Particle count or volume standard or control [e.g., platelet count standards, etc.]
• CPC Class Codes: Y10T 436/109163 Inorganic standards or controls

Abstract

A microsphere-based analytic chemistry system is disclosed in which self-encoding microspheres having distinct characteristic optical response signatures to specific target analytes may be mixed together while the ability is retained to identify the sensor type and location of each sensor in a random dispersion of large numbers of such sensors in a sensor array using an optically interrogatable encoding scheme. An optical fiber bundle sensor is also disclosed in which individual microsphere sensors are disposed in microwells at a distal end of the fiber bundle and are optically coupled to discrete fibers or groups of fibers within the bundle. The identities of the individual sensors in the array are self-encoded by exposing the array to a reference analyte while illuminating the array with excitation light energy. A single sensor array may carry thousands of discrete sensing elements whose combined signal provides for substantial improvements in sensor detection limits, response times and signal-to-noise ratios.

Claims

1. A method of detecting a plurality of target analytes, comprising:

(a) providing an array comprising different sensor elements at individual sites of a substrate, wherein said array comprises subpopulations of sensor elements having sensor redundancy;

(b) contacting said array with a sample comprising a plurality of target analytes under conditions wherein said target analytes bind to said sensor elements, thereby producing signals at said individual sites from said sensor elements;

(c) detecting said signals at said individual sites independently; and

(d) combining said signals for each of said subpopulations of sensor elements, wherein the signal-to-noise ratio is increased as a result of said combining of said signals, thereby detecting said plurality of target analytes.

2. The method of claim 1, further comprising performing a statistical analysis on said signals for each of said subpopulations of sensor elements.

3. The method of claim 1, further comprising determining statistical validity of said signals for each of said subpopulations of sensor elements.

4. The method of claim 1, further comprising determining outlying signals.

5. The method of claim 4, further comprising removing outlying signals prior to said combining.

6. The method of claim 1, wherein each of said subpopulations of sensor elements comprises 10 or more sensor elements to provide said sensor redundancy.

7. The method of claim 1, wherein each of said subpopulations of sensor elements comprises from 2 to 100 sensor elements to provide said sensor redundancy.

8. The method of claim 1, wherein each of said subpopulations of sensor elements comprises from 5 to 50 sensor elements to provide said sensor redundancy.

9. The method of claim 1, wherein said sensor elements of each of said subpopulations comprises the same bioactive agent.

10. The method of claim 1, wherein said sensor elements comprise nucleic acids.

11. The method of claim 1, wherein said target analytes comprise nucleic acids.

12. The method of claim 11, wherein said target analytes comprise single nucleotide polymorphisms.

13. The method of claim 12, further comprising genotyping said sample.

14. The method of claim 1, wherein said sensor elements comprise beads.

15. The method of claim 1, wherein said array comprises beads in wells.

16. The method of claim 15, wherein each well contains a single bead.

17. The method of claim 1, wherein said individual sites are contiguous.

18. The method of claim 1, wherein said individual sites comprise beads on the interior surface of a tube.

19. The method of claim 1, wherein said beads are randomly disbursed in said array.

20. The method of claim 1, wherein said substrate comprises a fiber optic bundle.

21. The method of claim 1, wherein said signals comprise optical signals.

22. The method of claim 1, wherein said detecting comprises detecting the presence of a label attached to said target analyte.

23. The method of claim 1, wherein said combining comprises summing said signals for each of said subpopulations of sensor elements.

24. The method of claim 1, further comprising identifying the location of each of said sensor elements within each of said subpopulations.