Detection signal and capture in dipstick assays

• US 20040053256A1
• Filed: 01/06/2003
• Published: 03/18/2004
• Est. Priority Date: 07/07/2000
• Status: Abandoned Application

• Current Assignee: Diagnostics for the Real World, Ltd.
• Original Assignee: Diagnostics for the Real World, Ltd.
• Inventors: Dineva, Magda Anastassova, Lee, Helen
• Application Number:
  US10/332,133
• Publication Number:
  US 20040053256A1
• Time in Patent Office: Days
• US Class Current: 435/6
• CPC Class Codes: B01L 3/5023 with a sample being transported to, and subsequently stored in an absorbent for analysis
• CPC Class Codes: C12Q 1/6816 characterised by the detection means C12Q1/6804 takes precedence
• CPC Class Codes: C12Q 1/6818 involving interaction of two or more labels, e.g. resonant energy transfer
• CPC Class Codes: C12Q 2565/625 being a nucleic acid test strip device, e.g. dipsticks, strips, tapes, CD plates

Abstract

Process for the production of methylenedianiline and its higher homologous products which comprises reacting aniline, or one of its derivatives, and formaldehyde, or one of its precursors, in one or two reactors in the presence of a solid acid catalyst selected from a zeolite or a silico-alumina, distilling the reaction water or the water added with the reagents.

Claims

1. A kit for testing for the presence of target nucleic acid in a sample solution which comprises:

i) a dipstick comprising;

a chromatographic strip having a contact end for contacting the sample solution;

a capture moiety, immobilised at a capture zone remote from the contact end;

ii) a plurality of capture probes, each capture probe being capable of hybridising to a different region of the target nucleic acid and each capture probe capable of being bound by the capture moiety when the capture probe has hybridised to the target nucleic acid; and

optionally

iii) a detection probe capable of hybridising to the target nucleic acid and thereby allowing detection of the target nucleic acid utilising the detection probe, the detection probe being releasably immobilised to a probe zone of the chromatographic strip located between the contact end and the capture zone of the chromatographic strip, or the detection probe being separate from the dipstick.

3. A kit according to claim 1 or a dipstick according to claim 2 in which each capture probe comprises a capture ligand which can be bound by the capture moiety to bind the capture probe to the capture moiety.

4. A kit or dipstick according to claim 3 in which each capture probe comprises a plurality of capture ligands each of which can be bound by the capture moiety.

5. A kit or dipstick according to any of claims 1 to 4 in which the detection probe comprises a label allowing direct detection of the target nucleic acid utilising the detection probe, or in which the detection probe comprises a detection ligand allowing indirect detection of the target nucleic acid utilising the detection probe.

6. A kit or dipstick according to claim 5 in which the detection probe comprises a plurality of labels or a plurality of detection ligands.

7. A kit or dipstick according to any of claims 1 to 4 in which the detection probe is a plurality of detection probes, each detection probe being capable of hybridising to a different region of the target nucleic acid and thereby allowing detection of the target nucleic acid utilising the detection probe.

8. A kit according to claim 7 in which each detection probe comprises a plurality of labels or a plurality of detection ligands.

21. A kit or dipstick according to any preceding claim in which the capture moiety comprises a capture probe capable of hybridising to the target nucleic acid or to a hook capture probe bound to the target nucleic acid.

26. Use of a dipstick according to any preceding claim for testing for the presence of target nucleic acid in a sample solution.

27. Use according to claim 26 in which the target nucleic acid is Chlamydia trachomatis nucleic acid.

2. A dipstick for testing for the presence of target nucleic acid in a sample solution which comprises:

a chromatographic strip having a contact end for contacting the sample solution;

a capture moiety, immobilised at a capture zone remote from the contact end; and

a plurality of capture probes releasably immobilised at a probe zone of the chromatographic strip located between the contact end and the capture zone, each capture probe being capable of hybridising to a different region of the target nucleic acid and each capture probe capable of being bound by the capture moiety when the capture probe has hybridised to the target nucleic acid.

9. A kit for testing for the presence of target nucleic acid in a sample solution which comprises:

i) a dipstick comprising;

a chromatographic strip having a contact end for contacting the sample solution; and

a capture moiety immobilised at a capture zone remote from the contact end;

ii) a capture probe capable of hybridising to the target nucleic acid, wherein the capture probe comprises a plurality of capture ligands each of which can be bound by the capture moiety when the capture probe has hybridised to the target nucleic acid; and

optionally

iii) a detection probe capable of hybridising to the target nucleic acid and thereby allowing detection of the target nucleic acid utilising the detection probe, the detection probe being releasably immobilised to a probe zone of the chromatographic strip located between the contact end and the capture zone of the chromatographic strip, or the detection probe being separate from the dipstick.

10. A dipstick for testing for the presence of target nucleic acid in a sample solution which comprises:

a chromatographic strip having a contact end for contacting the sample solution;

a capture moiety immobilised at a capture zone remote from the contact end; and

a capture probe releasably immobilised to a probe zone of the chromatographic strip located between the contact end and the capture zone, the capture probe being capable of hybridising to the target nucleic acid, wherein the capture probe comprises a plurality of capture ligands each of which can be bound by the capture moiety when the capture probe has hybridised to the target nucleic acid.

11. A kit according to claim 9 or a dipstick according to claim 10 in which the detection probe comprises a label allowing direct detection of the target nucleic acid utilising the detection probe, or in which the detection probe comprises a detection ligand allowing indirect detection of the target nucleic acid utilising the detection probe.

12. A kit or dipstick according to claim 11 in which the detection probe comprises a plurality of labels or detection ligands.

13. A kit according to claim 9 or a dipstick according to claim 10 in which the detection probe is a plurality of detection probes, each detection probe being capable of hybridising to a different region of the target nucleic acid and thereby allowing detection of the target nucleic acid utilising the detection probe.

14. A kit or dipstick according to claim 13 in which each detection probe comprises a plurality of labels or detection ligands.

24. A kit or dipstick according to any of claims 5, 6, 8, 11, 12, 14 or 17 to 20 in which the or each label is non radioactive.

25. A kit or dipstick according to any of claims 3, 4, 9, 10, or 22 in which the capture moiety comprises an antibody or antibody fragment capable of binding to the or each capture ligand.

15. A kit for testing for the presence of target nucleic acid in a sample solution which comprises:

i) a dipstick comprising;

a chromatographic strip having a contact end for contacting the sample solution; and

a capture moiety immobilised at a capture zone remote from the contact end the capture moiety being capable of binding directly or indirectly to the target nucleic acid; and

ii) a plurality of detection probes, each detection probe being capable of hybridising to a different region of the target nucleic acid and thereby allowing detection of the target nucleic acid utilising the detection probes.

17. A kit according to claim 15 or a dipstick according to claim 16 in which each detection probe comprises a label allowing direct detection of the target nucleic acid utilising the detection probe, or in which each detection probe comprises a detection ligand allowing indirect detection of the target nucleic acid utilising the detection probe.

18. A kit or dipstick according to claim 17 in which each detection probe comprises a plurality of labels or a plurality of detection ligands.

22. A kit or dipstick according to any of claims 15 to 20 in which the capture moiety comprises a capture ligand binding moiety capable of binding to a capture ligand of a capture probe, the capture probe being capable of hybridising to the target nucleic acid so that the capture moiety can thereby bind indirectly to the target nucleic acid.

23. A kit or dipstick according to claim 22 further comprising the capture probe.

38. A method for testing for the presence of target nucleic acid in a sample solution which comprises:

providing a dipstick as specified in claim 15;

contacting the sample solution with a plurality of detection probes, each detection probe being capable of hybridising to a different region of the target nucleic acid thereby allowing direct or indirect detection of the target nucleic acid utilising the detection probes, the detection probes being incubated with the sample solution under conditions for hybridisation of the detection probes with the target nucleic acid;

contacting the contact end of the dipstick with the sample solution to cause sample solution to move by capillary action to the capture zone, thereby allowing target nucleic acid and detection probes to move with the sample solution to the capture zone, and target nucleic acid to be captured at the capture zone; and

detecting for the detection probes at the capture zone.

16. A dipstick for testing for the presence of target nucleic acid in a sample solution which comprises:

a chromatographic strip having a contact end for contacting the sample solution;

a capture moiety immobilised at a capture zone remote from the contact end, the capture moiety being capable of binding directly or indirectly to the target nucleic acid; and

a plurality of detection probes releasably immobilised at a probe zone of the chromatographic strip located between the contact end and the capture zone, each detection probe being capable of hybridising to a different region of the target nucleic acid and thereby allowing detection of the target nucleic acid utilising the detection probes.

39. A method for testing for the presence of target nucleic acid in a sample solution which comprises:

providing a dipstick as specified in claim 16 or 20;

contacting the contact end of the dipstick with the sample solution to cause sample solution to move by capillary action to the capture zone, thereby allowing target nucleic acid in the sample solution to be captured at the capture zone and releasing the or each detection probe into the sample solution so that the or each detection probe can hybridise to target nucleic acid; and

detecting for the or each detection probe at the capture zone.

19. A kit for testing for the presence of target nucleic acid in a sample solution which comprises:

i) a dipstick comprising;

a chromatographic strip having a contact end for contacting the sample solution;

a capture moiety immobilised at a capture zone remote from the contact end, the capture moiety being capable of binding directly or indirectly to the target nucleic acid; and

ii) a detection probe capable of hybridising to the target nucleic acid, wherein the detection probe comprises a plurality of labels allowing direct detection of the target nucleic acid utilising the detection probe, or wherein the detection probe comprises a plurality of detection ligands allowing indirect detection of the target nucleic acid utilising the detection probe.

40. A method for testing for the presence of target nucleic acid in a sample solution which comprises:

providing a dipstick as specified in claim 19;

contacting the sample solution with a detection probe capable of hybridising to the target nucleic acid, wherein the detection probe comprises a plurality of labels allowing direct detection of the target nucleic acid utilising the detection probe, or wherein the detection probe comprises a plurality of detection ligands allowing indirect detection of the target nucleic acid utilising the deteciton probe, the detection probe being incubated with the sample solution under conditions for hybridisation of the detection probe with the target nucleic acid;

contacting the contact end of the dipstick with the sample solution to cause sample solution to move by capillary action to the capture zone, thereby allowing target nucleic acid and detection probe to move with the sample solution to the capture zone, and target nucleic acid to be captured at the capture zone; and

detecting for the detection probe at the capture zone.

20. A dipstick for testing for the presence of target nucleic acid in a sample solution which comprises:

a chromatographic strip having a contact end for contacting the sample solution;

a capture moiety immobilised at a capture zone remote from the contact end, the capture moiety being capable of binding directly or indirectly to the target nucleic acid; and

a detection probe releasably immobilised at a probe zone of the chromatographic strip located between the contact end and the capture zone, the detection probe being capable of hybridising to the target nucleic acid, wherein the detection probe comprises a plurality of labels allowing direct detection of the target nucleic acid utilising the detection probe, or wherein the detection probe comprises a plurality of detection ligands allowing indirect detection of the target nucleic acid utilising the detection probe.

28. A probe for detecting or capturing target nucleic acid which comprises a nucleic acid or nucleic acid analogue capable of hybridising to the target nucleic acid, wherein the nucleic acid or nucleic acid analogue is coupled to a plurality of labels allowing direct detection of the target nucleic acid when the probe has hybridised to the target nucleic acid, or wherein the nucleic acid is coupled to a plurality of ligands which can be bound by a ligand binding moiety to detect or capture the target nucleic acid when the probe has hybridised to the target nucleic acid.

29. A probe according to claim 28 in which for each label or ligand of the plurality of labels or ligands a linker [as herein defined] covalently couples the label or ligand to the nucleic acid or nucleic acid analogue.

30. A probe according to claim 28 in which the plurality of labels or ligands are covalently coupled to the nucleic acid or nucleic acid analogue by a branched linker [as herein defined].

31. A probe according to claim 29 or 30 in which the or each linker comprises a non-nucleotide, preferably polyethylene glycol.

32. A probe according to any of claims 29 to 31 in which the or each linker is covalently coupled to the nucleic acid or nucleic acid analogue by a spacer.

33. A probe according to claim 32 in which the spacer comprises a nucleotide or hexaethyleneglycol phosphate.

34. A probe according to any of claims 28 to 33 in which the label is a nonradioactive label.

35. Use of a probe according to any of claims 28 to 34 in a dipstick assay for testing for the presence of target nucleic acid in a sample solution.

36. Use of a plurality of different capture probes in a dipstick assay for testing for the presence of a target nucleic acid in a sample solution, each capture probe being capable of hybridising to a different region of the target nucleic acid, thereby allowing capture of the target nucleic acid to the dipstick by a capture moiety;

immobilised to the dipstick, capable of binding the capture probes.

37. Use of a plurality of different detection probes in a dipstick assay for testing for the presence of a target nucleic acid in a sample solution, each detection probe being capable of hybridising to a different region of the target nucleic acid, thereby allowing detection of the target nucleic acid utilising the detection probe.

41. A method for testing for the presence of a target nucleic acid in a sample solution which comprises:

a) providing a chromatographic strip having a contact end for contacting the sample solution and a capture moiety immobilised at a capture zone of the chromatographic strip remote from the contact end, the capture moiety being capable of binding directly or indirectly to the target nucleic acid;

b) contacting the contact end of the chromatographic strip with the sample solution to cause sample solution to move by capillary action to the capture zone so that target nucleic acid in the sample solution can be captured at the capture zone by the capture moiety;

(c) either;

(i) contacting the capture zone with a plurality of detection probes, each detection probe being capable of hybridising to a different region of the target nucleic acid and thereby allowing detection of the target nucleic acid utilising the detection probes;

or (ii) contacting the capture zone with a detection probe capable of hybridising to the target nucleic acid thereby allowing detection of the target nucleic acid utilising the detection probe, wherein the detection probe comprises a plurality of labels allowing direct detection of the target nucleic acid utilising the detection probe, or wherein the detection probe comprises a plurality of detection ligands allowing indirect detection of the target nucleic acid utilising the detection probe;

d) removing unbound detection probe from the capture zone of the chromatographic strip; and

e) detecting for the presence of the or each detection probe at the capture zone.

42. A method for testing for the presence of target nucleic acid in a sample solution which comprises:

providing a dipstick comprising a chromatographic strip having a contact end for contacting the sample solution and a capture moiety immobilised at a capture zone of the chromatographic strip remote from the contact end;

contacting the sample solution with a plurality of capture probes, each capture probe being capable of hybridising to a different region of the target nucleic acid and each capture probe capable of being bound by the capture moiety when the capture probe has hybridised to the target nucleic acid;

contacting the sample solution with the contact end of the chromatographic strip to cause sample solution to move by capillary action to the capture zone, thereby allowing a complex comprising target nucleic acid and the capture probes to be captured at the capture zone by binding of the capture moiety to the capture probes; and

detecting for target nucleic acid at the capture zone.

43. A method for testing for the presence of target nucleic acid in a sample solution which comprises:

providing a dipstick comprising a chromatographic strip having a contact end for contacting the sample solution and a capture moiety immobilised at a capture zone of the chromatographic strip remote from the contact end;

contacting the sample solution with a capture probe capable of hybridising to the target nucleic acid, wherein the capture probe comprises a plurality of capture ligands, each of which can be bound by the capture moiety when the capture probe has hybridised to the target nucleic acid;

contacting the sample solution with the contact end of the chromatographic strip to cause sample solution to move by capillary action to the capture zone, thereby allowing a complex comprising target nucleic acid and capture probe to be captured at the capture zone by binding of the capture moiety to the capture probe; and

detecting for target nucleic acid at the capture zone.

44. A method for testing for the presence of target nucleic acid in a sample solution which comprises:

providing a dipstick comprising a chromatographic strip having;

a contact end for contacting the sample solution;

a capture moiety immobilised at a capture zone of the chromatographic strip remote from the contact end; and

a plurality of capture probes releasably immobilised to the chromatographic strip between the contact end and the capture zone, each capture probe being capable of hybridising to a different region of the target nucleic acid and each capture probe capable of being bound by the capture moiety when the capture probe has hybridised to the target nucleic acid;

contacting the sample solution with the contact end of the chromatographic strip to cause sample solution to move by capillary action to the capture zone, thereby releasing the capture probes from the chromatographic strip so that they can hybridise to target nucleic acid in the sample solution as it moves to the capture zone and allowing a complex comprising target nucleic acid and the capture probes to be captured at the capture zone by binding of the capture moiety to the capture probes; and

detecting for target nucleic acid at the capture zone.

45. A method for testing for the presence of target nucleic acid in a sample solution which comprises:

providing a dipstick comprising a chromatographic strip having;

a contact end for contacting the sample solution;

a capture moiety immobilised at a capture zone of the chromatographic strip remote from the contact end; and

a capture probe capable of hybridising to the target nucleic acid, the capture probe being releasably immobilised to the chromatographic strip between the contact end and the capture zone, wherein the capture probe comprises a plurality of capture ligands, each of which can be bound by the capture moiety when the capture probe has hybridised to the target nucleic acid;

contacting the sample solution with the contact end of the chromatographic strip to cause sample solution to move by capillary action to the capture zone, thereby releasing the capture probe from the chromatographic strip so that it can hybridise to target nucleic acid in the sample solution as the sample solution moves to the capture zone and allowing a complex comprising target nucleic acid and the capture probe to be captured at the capture zone by binding of the capture moiety to the capture probe; and

detecting for target nucleic acid at the capture zone.

46. A method for testing for the presence of target nucleic acid in a sample solution which comprises:

providing a dipstick comprising a chromatographic strip having a contact end for contacting the sample solution and a capture moiety immobilised at a capture zone of the chromatographic strip remote from the contact end;

providing a plurality of capture probes, each capture probe being capable of binding to the capture moiety and hybridising to a different region of the target nucleic acid;

binding the plurality of capture probes to the capture moiety;

contacting the sample solution with the contact end of the chromatographic strip to cause sample solution to move by capillary action to the capture zone, thereby allowing target nucleic acid in the sample solution to be captured at the capture zone by binding of the target nucleic acid to the plurality of capture probes; and

detecting for target nucleic acid at the capture zone.

47. A method for testing for the presence of target nucleic acid in a sample solution which comprises:

providing a dipstick comprising a chromatographic strip having a contact end for contacting the sample solution and a capture moiety immobilised at a capture zone of the chromatographic strip remote from the contact end;

providing a plurality of capture probes, each capture probe being capable of binding to the capture moiety and hybridising to a different region of the target nucleic acid;

binding the plurality of capture probes to the capture moiety;

contacting the sample solution with the contact end of the chromatographic strip to cause sample solution to move by capillary action to the capture zone, thereby allowing target nucleic acid in the sample solution to be captured at the capture zone by binding of the target nucleic acid to the plurality of capture probes; and

detecting for target nucleic acid at the capture zone.