Imaging immunoassay detection system with background compensation and its use

• US 5,096,807 A
• Filed: 12/01/1989
• Issued: 03/17/1992
• Est. Priority Date: 03/06/1985
• Status: Expired due to Term

• Current Assignee: DX Company Limited
• Original Assignee: Murex Corporation
• Inventors: Leaback, David H.
• Primary Examiner(s): Lacey, David L.
• Assistant Examiner(s): CHAN, KWONG
• Application Number:
  US07/449,502
• Time in Patent Office: 837 Days
• Field of Search: 435/7.1, 435/7.4, 435/7.92, 435/288, 435/291, 435/965, 435/973, 435/6, 436/512, 436/513, 935/77, 935/86, 422/50, 422/52, 422/82.08
• US Class Current: 435/6.11
• CPC Class Codes: B01J 2219/00605 the compounds being directly bound or immobilised to solid supports
• CPC Class Codes: B01J 2219/00612 the surface being inorganic
• CPC Class Codes: B01J 2219/00619 using hydrophilic or hydrophobic regions
• CPC Class Codes: B01J 2219/00626 Covalent
• CPC Class Codes: B01J 2219/00659 Two-dimensional arrays
• CPC Class Codes: B01J 2219/00707 separated from the reactor apparatus
• CPC Class Codes: G01N 21/76 Chemiluminescence; Bioluminescence
• CPC Class Codes: G01N 2201/04 Batch operation; multisample devices
• CPC Class Codes: G01N 33/535 with enzyme label or co-enzymes, co-factors, enzyme inhibitors or enzyme substrates
• CPC Class Codes: G01N 33/542 with steric inhibition or signal modification, e.g. fluorescent quenching
• CPC Class Codes: G01N 33/54373 involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings
• CPC Class Codes: Y10S 435/965 involving idiotype or anti-idiotype antibody
• CPC Class Codes: Y10S 435/973 Simultaneous determination of more than one analyte

Abstract

The invention provides an imaging immunoassay detection apparatus system and method capable of detecting multiple light emitting reactions from small volume samples simultaneously and quantifying the same.

Claims

1. A system for detecting photons generated by chemical reactions comprising:

a. sample carrier means having a plurality of individual discrete separated areas each containing a separate and independent chemical reactant sample which will emit a number of light photons when a reaction takes place, said plurality of reactant-containing discrete separated areas being arranged in two-dimensional spaced relationship with respect to each other and having spaces therebetween;

b. photon-receiving means associated with said sample carrier means for simultaneously receiving individual photons emitted from each discrete area sample and from said spaces when photons are emitted from said spaced; and

c. signal generating means coupled to said photon-receiving means for generating signals representing a location of each of said discrete area sample and each of said spaces generating a photon, whereby the sample location of each area having a reaction, the location of each of said spaces generating a photon and said number of their photon emissions over any predetermined period of time will be simultaneously identified.

2. A system as in claim 1 wherein:

a. said photon-receiving means is constructed so as to respond to photons emitted from said spaces for generating signals representing background noise which consists of emitted light photons from said spaces between said chemical reactant samples; and

b. wherein there is included means for subtracting said background noise signals from said signals representing photon emission from each of said samples to produce a resulting signal whereby said resulting signal represents substantially only pure emissions from said reactant samples.

3. A system as in claim 1 further including:

a. computing means coupled to said signal generating means for receiving and storing each of said signals whereby said location of each of said spaces generating a photon and the number of photons generated by each of said spaces and each sample having a reaction over said any predetermined period of time can be accessed; and

b. display means coupled to said computing means for presenting a representation of each of said samples and the number of its photon emissions.

4. A system as in claim 2 further including:

a. computing means coupled to said signal generating means for receiving and storing each of said signals whereby said location of each of said spaces generating a photon and the number of photons generated by each of said spaces and each sample having a reaction over said any predetermined period of time can be accessed; and

b. display means coupled to said computing means for presenting a representation of each of said samples and the number of its photon emissions.

5. A system as in claim 3 wherein said display means is a video display.

6. A system as in claim 4 wherein said display means is a printer.

7. A system as in claim 3 wherein said computing means is a microprocessor.

8. A system as in claim 1 wherein said signal generating means is a photomultiplier tube having a photoconductive target for producing reaction location output signals representing the number of photons emitted by each reaction, and the space output signals representing the number of photons emitted by said spaces.

9. A system as in claim 1 wherein said signal generating means is a charge coupled device for producing reaction location output signals representing the number of photons emitted by each reaction, and the number of photons emitted by said spaces.

10. A system as in claim 1 wherein said signal generating means is a vidicon tube for producing reaction location output signals representing the number of photons emitted by each reaction and the number of photons emitted by said spaces.

11. A system as in claim 4 wherein each of said chemical reactant samples comprises:

a. an antibody;

b. an antigen; and

c. an indicator which labels said antibody and which generates said photons of light when a reaction occurs between said antibody and said antigen.

12. A system as in claim 3 wherein at least one of said chemical reactant samples contains an indicator which emits light of different wavelength than others of said chemical reactant samples.

13. A system as in claim 12 further comprising:

a. a photoconductive target forming a portion of said signal generating means; and

b. an optics system constructed so as to focus light photons from said reactant samples on said photoconductive target to generate said sample location output signals representing the number of said photon emissions from each said sample.

14. A system as in claim 13 further comprising a specific wavelength light interference filter positioned between said sample carrier means and said optics system for passing only a specific light wavelength corresponding to said at least one chemical reactant indicator being said indicator which emits light of different wavelength than said others of said chemical reactant samples whereby only said at least on chemical reactant is monitored by said system for photon emission.

15. A system as in claim 2 wherein said photon emitting reactant samples are arranged in discrete areas forming a single row or column.

16. A system as in claim 2 wherein said photon emitting reactant samples are arranged in discrete areas forming a two-dimensional array of rows and columns.

17. A system as in claim 15 or 16 further including:

a. a first reactant sample in one of said discrete areas;

b. a second different reactant sample in a second one of said discrete areas; and

c. means for comparing signals representing light photons emitted from said second reactant sample with signals representing light photons emitted from said first reactant sample, whereby one reactant sample may be compared with another.

18. A system as in claim 17 wherein said second reactant sample is a test sample and said first reactant sample is a control sample representing a desired standard control reaction, whereby said test sample may be compared with said control sample.

19. A system as in claim 2 wherein:

a. said signals generated by said signal generating means include photon representation analog signals severally representing the numbers of photons generated by each photon-generating sample over a predetermined period of time, and further including

b. an analog-to-digital converter coupled to said signal generating means for converting said analog signals representing said numbers of photons to digital signals;

c. a microprocessor coupled to said analog-to-digital converter; and

d. storage means in said microprocessor having a plurality of locations therein corresponding to said plurality of reactant samples for storing said digital signals.

20. A system as in claim 2 wherein each of said chemical reactant samples comprises:

a. a sample containing a sequence of nucleic acids;

b. a nucleic acid probe specific for its complementary sequence in nucleic acids respectively; and

c. an indicator which labels said nucleic acid probe and which generates said photons of light when a reaction occurs between said probe and its said complementary sequence.

21. A system as in claim 2 wherein each of said chemical reactant samples comprises:

a. an isotope-labeled antibody;

b. an analyte of interest whereby when a reaction occurs between said labeled antibody and said analyte of interest, gamma rays are generated; and

c. a phosphor screen for receiving said gamma rays and generating said photons of light.

22. A system as in claim 1 wherein:

a. said photon receiving-means is constructed so as to respond to photons emitted from said spaces for generating signals representing background noise which consists of emitted light photons from said spaces between said reactant samples; and

b. wherein there is included means for substracting said background noise signals from said signals representing photon emission from each of said samples whereby the resulting signal represents substantially only pure emissions from said reactant samples.

23. A system as in claim 22 further including:

a. computing means coupled to said signal generating means for receiving and storing each of said signals whereby the location and number of photons generated by each of said spaces and each sample having a reaction over said any predetermined period of time can be accessed; and

b. display means coupled to said computing means for presenting a representation of each of said samples and the number of its photon emissions.

24. A system as in claim 23 wherein said display means is a video display.

25. A system as in claim 23 wherein said display means is a printer.

26. A method of detecting photons generated by a chemical reaction comprising:

a. proving a plurality of discrete separated individual and independent chemical reactant samples each capable of reacting with a specific substance and emitting light photons when a reaction takes place, said reactant samples being arranged in two-dimensional spaced apart relationship with each other;

b. creating spaces of predetermined size between said reactant samples, said spaces emitting spurious photons representing background noise;

c. adding to each of said samples a specimen potentially containing at least one unknown specific substance such that a reaction generating photons occurs when said specific substance is present in said specimen;

d. simultaneously generating first signals detecting presence of each photon emitted within each of said spaces and from any of said samples and a location of each of said reactant samples from which a photon is emitted, whereby a total number of photons emitted from said spaces and from each individual reactant sample over a predetermined period of time will be determined, and generating a background signal representing background noise.

27. A method of detecting photons generated by a chemical reaction as in claim 26 further including accumulating the number of photons emitted by any reactant samples over a predetermined period of time whereby the total photon emission of any reactant sample may be determined.

28. A method of detecting photons generated by a chemical reaction as in claim 26 further including subtracting said signal representing background noise from said first signals thereby to create other signals representing pure emissions from said reactant samples.

29. A method of detecting photons generated by a chemical reaction as in claim 26 further including storing in a microprocessor numbers severally corresponding to the numbers of photons emitted by said reactant samples over a predetermined period of time, thereby enabling the photon emissions of any reactant sample to be compared with the number of photon emissions from other reactant samples.

30. A method of detecting photons generated by a chemical reaction as in claim 29 further including displaying for each reactant sample a representation of the total accumulation of the number of photons emitted by that sample over a predetermined period of time thereby giving a visual indication of the number of photons emitted by said each reactant sample over said predetermined period of time.

32. A method as in one of claims 26 31 wherein said at least one unknown substance is an antigen and further comprising contacting at least a portion of said specimen with a labeled monoclonal antibody.

33. A method as in claim 26 further including utilizing an imaging detector to detect presence and location of each photon emitted by any of said reacting samples.

34. A method as in claim 33 further including utilizing an imaging photon detector as said imaging detector.

35. A method as in claim 33 further including utilizing a charge coupled device as said imaging detector.

36. A method as in claim 33 further including utilizing a vidicon tube as said imaging detector.

37. A method as in claim 26 further comprising forming each of said reactant samples with an antibody, an antigen, and an indicator which labels said antibody and which generates said light photons when a reaction occurs between said antibody and said antigen.

38. A method as in claim 37 further including forming at least one of said chemical reactants with an indicator which emits light of different wavelength than others of said chemical reactants indicators.

39. A method as in claim 38 further including:

a. forming a portion of said photon detecting means as a photoconductive target; and

b. focusing said light photons from said reactant samples on said photoconductive target with an optics system to generate signals representing presence and location of said photon emissions from said samples.

40. A method as in claim 39 further including positioning a specific wavelength light interference filter between said reactant samples and said optics system for passing only a specific light wavelength corresponding to said at least one of said chemical reactants indicators being said indicator which emits light of different wavelength than the others of said chemical reactants indicators whereby only said at least one chemical reactants is monitored by said system for photon emission.

41. A method as in claim 26 further including:

a. detecting background noise signals consisting of said spurious light photons emitted from said spaces between said reactant samples; and

b. subtracting said background noise signals from said signals representing photon emissions from each of said samples whereby a resulting signal represents substantially only pure photon emissions from said reactant samples.

42. A method as in claim 26 further comprising arranging said photon emitting reactant samples in discrete areas forming a single linear sequence of either a row or column.

43. A method as in claim 26 further comprising arranging said photon emitting reactant samples in discrete areas forming a two-dimensional array of rows and columns.

44. A method as in claim 42 or 43 further comprising:

a. placing a first reactant sample in one of said discrete areas;

b. placing a second different reactant sample in a second one of said discrete areas; and

c. comparing signals representing the number of light photons emitted from said sample in said second one of said areas with said signals representing light photons emitted from said first sample whereby one sample may be compared with another.

45. A method as in claim 44 further comprising:

a. forming said first sample of reactants providing a desired standard control reaction; and

b. forming said second reactant sample as a test sample whereby said test sample may be compared with said control sample.

46. A method as in claim 26 wherein the step of generating first signals detecting the presence of each photon emitted and the location of each of said reactant samples from which a photon is emitted is the step of generating analog signals.

47. A method as in claim 46 further including:

a. converting said analog signals to digital signals;

b. coupling said digital signals to a microprocessor; and

c. storing said digital signals in a plurality of memory locations in said microprocessor.

48. A method of detecting photons generated by a chemical reaction as in claim 26 further including the step of subtracting said background signal representing background noise from said first signals thereby to create other signals representing pure emissions from said reactant samples.

31. A method for detecting a reaction comprising:

a. locating a plurality of labeled compounds onto discreet and separated areas of a carrier;

b. adding to at least one of said labeled compounds a specimen potentially containing at least one unknown substance of a type which produces a reaction with said at least one of said labeled compounds when said unknown substance is present and comprises a particular substance, any said reaction generating light photons;

c. individually detecting any of said reaction that may occur by simultaneously detecting location of any said reaction and number of light photons emitted by each said reaction;

d. detecting any spurious photons emitted in spaces between said discreet and separated areas of said carrier and generating from said spurious photons a background noise signal representing background noise for said carrier; and

e. adjusting said number of photons thereby to essentially eliminate any noise component therefrom.