Electrophoresis apparatus and a plate therefor

• US 20040007465A1
• Filed: 07/14/2003
• Published: 01/15/2004
• Est. Priority Date: 08/01/2000
• Status: Active Grant

• Current Assignee: Sensis Pty Limited (Telstra Group Ltd.)
• Original Assignee: Sensis Pty Limited (Telstra Group Ltd.)
• Inventors: Weissman, Zeev, Ruschin, Shlomo, Goldberg, Doron, Shapiro, Menachem
• Granted Patent: US 7,384,527 B2
• Time in Patent Office: Days
• US Class Current: 204/452
• CPC Class Codes: G01N 27/44704 Details; Accessories
• CPC Class Codes: G01N 27/44721 by optical means
• CPC Class Codes: G01N 27/44791 Microapparatus sample containers with integrated microfluidic structures B01L3/5027

Abstract

The invention provides an electrophoresis apparatus comprising an electrophoretic chamber containing at least on two-plate housing for a sieving matrix, each said at least one two-plate housing consisting of a cover plate and a plate for housing said sieving matrix, wherein said plate includes an optical waveguide array which is characterized by being aligned with respect to a reference direction such as to enable one or more light beams incident on the sieving matrix along said reference direction to be maintained well-confined along said reference direction within any desired length of interaction along the width of said sieving matrix.

Claims

1. A plate for housing a sieving matrix for electrophoresis of a sample, said plate including an optical waveguide array which is characterized by being aligned with respect to a reference direction such as to enable one or more light beams incident on the sieving matrix along said reference direction to be maintained well-confined along said reference direction within any desired length of interaction along the width of said sieving matrix.

2. A plate according to claim 1, wherein said sieving matrix is a gel which is transparent with respect to said incident light beams.

3. A plate according to claim 2, wherein said gel is polyacrylamide or a derivative thereof

4. A plate according to any one of claims 1 to 3, wherein said optical waveguide array contains one sole waveguide.

5. A plate according to any one of claims 1 to 3, wherein said optical waveguide array contains a plurality of waveguides.

6. A plate according to any one of claims 1 to 5, wherein said optical waveguide comprises at least one waveguiding unit, each said waveguiding unit characterized in enabling diffracted light beam in the sieving matrix along said reference direction, incident with respect to said waveguiding unit, to be refocused along said reference direction, thereby maintaining a well-confined light beam within at least a portion of said sieving matrix along said reference direction.

7. A plate according to claim 6, wherein said waveguide comprises a plurality of said waveguiding units aligned in series along said reference direction.

8. A plate according to claim 6 or 7, wherein at least one said waveguiding unit is a convex-shaped lens.

9. A plate according to claim 8, wherein said convex-shaped lens is formed as a protrusion extending in a direction orthogonal to said reference direction.

10. A plate according to claim 8, wherein said convex-shaped lens is formed as a fiber optic segment extending in a direction orthogonal to said reference direction.

11. A plate according to any one of claims 6 to 10, wherein at least one said waveguiding unit is substantially cylindrical having a central axis in a direction substantially orthogonal both to said reference direction and to a direction of migration of said sample with respect to said sieving matrix.

12. A plate according to any one of claims 1 to 11, wherein said light beam incident on the sieving matrix is delivered through at least one optical coupling element located at at least one of the edges of the waveguide and said light beam delivered though said optical coupling element is collimated by a collimator located before the first waveguiding unit.

13. A plate according to claim 12, wherein said at least one optical coupling element is an optical fiber element.

14. A plate according to claim 12 or 13, wherein said collimator is a convex-shaped lens.

15. A plate according to any one of claims 1 to 14, wherein said light beam is a laser beam.

16. A plate according to anyone of claims 1 to 15, wherein said plate is made of a plastic material.

17. A two-plate housing for a sieving matrix for electrophoresis of a sample comprising a plate according to any one of claims 1 to 16, and a cover plate.

18. A two-plate housing according to claim 17, wherein said cover plate is made of glass.

19. A two-plate housing according to claim 17, wherein said cover plate is made of plastic.

20. A two-plate housing according to any one of claims 17 to 19 comprising a precast sieving matrix.

21. A two-plate housing according to claim 20 containing a precast gel which is transparent with respect to said incident light beams.

22. A two-plate housing according to claim 21 wherein said gel is polyacrylamide or a derivative thereof.

54. A method for the detection of at least one substance by electrophoresis, which comprises:

(i) loading at least one sample comprising said at least one substance in at least one lane formed by a sieving matrix contained in a two-plate housing according to any one of claims 17 to 22;

(ii) running said at least one sample in said at least one lane in a first direction with a suitable buffer under a suitable applied electrical potential;

(iii) illuminating the sieving matrix with a light source such that the optical waveguide of the plate comprised within said two-plate housing enables the confining of the light beam along a second direction intersecting said first direction, whereby the interaction between said light beam with said at least one substance provides a change in an optical characteristic of said light beam or of said sieving matrix;

(iv) detecting said change in said optical characteristic with a suitable light detector; and

(v) processing the data generated by said detector.

55. A method according to claim 54, wherein said at least one substance is labeled with a suitable dye and the interaction between said light beam with said at least one labeled substance provides an increase in the absorbance in said sieving matrix and the emitted light along said second direction is detected by a light detector which detects variations of light.

56. A method according to claim 54, wherein said at least one substance is fluorescently labeled and the interaction between said light beam with said at least one labeled substance provides an increase in the fluorescence in said sieving matrix and the emitted fluorescence along a third direction is detected by a light detector which detects fluorescence photons.

57. A method according to any one of claims 54 to 56, wherein said at least one substance is a peptide, a protein, an SDS-denatured protein or a nucleic acid.

58. A method according to claim 54, wherein the interaction between said light beam with said at least one substance and with said sieving matrix provides a change in the refractive index in said sieving matrix and the emitted light is detected by a light detector which detects variations of light intensity which are due to the change in the refractive index in said sieving matrix.

59. A method according to claim 58, wherein said at least one substance is at least one protein or an SDS-denatured protein.

60. A method according to any one of claims 54 to 59, wherein said light beam is a laserbeam.

23. An electrophoresis apparatus comprising an electrophoretic chamber containing at least one two-plate housing for a sieving matrix, each said at least one two-plate housing consisting of a cover plate and a plate for housing said sieving matrix, wherein said plate includes an optical waveguide array which is characterized by being aligned with respect to a reference direction such as to enable one or more light beams incident on the sieving matrix along said reference direction to be maintained well-confined along said reference direction within any desired length of interaction along the width of said sieving matrix.

24. An electrophoresis apparatus according to claim 23, wherein said sieving matrix is a gel which is transparent with respect to said incident light beams.

25. An electrophoresis apparatus according to claim 24, wherein said gel is polyacrylamide or a derivative thereof.

26. An electrophoresis apparatus according to any one of claims 23 to 25, wherein said optical waveguide array contains one sole waveguide.

27. An electrophoresis apparatus according to any one of claims 23 to 25, wherein said optical waveguide array contains a plurality of waveguides.

28. An electrophoresis apparatus according to any one of claims 23 to 27, wherein each said optical waveguide comprises at least one waveguiding unit, each said waveguiding unit characterized in enabling diffracted light beam in the sieving matrix along said reference direction, incident with respect to said waveguiding unit, to be refocused along said reference direction, thereby maintaining a well-confined light beam within at least a portion of said sieving matrix along said reference direction.

29. An electrophoresis apparatus according to claim 28, wherein said waveguide comprises a plurality of said waveguiding units aligned in series along said reference direction.

30. An electrophoresis apparatus according to claims 28 or 29, wherein at least one said waveguiding unit is a convex-shaped lens.

31. An electrophoresis apparatus according to claim 30, wherein said convex-shaped lens is formed as a protrusion extending in a direction orthogonal to said reference direction.

32. An electrophoresis apparatus according to claim 30, wherein said convex-shaped lens is formed as a fiber optic segment extending in a direction orthogonal to said reference direction.

33. An electrophoresis apparatus according to any one of claims 28 to 32, wherein at least one said waveguiding unit is substantially cylindrical having a central axis in a direction substantially orthogonal both to said reference direction and to a direction of migration of said sample with respect to said sieving matrix.

34. An electrophoresis apparatus according to any one of claims 23 to 33, wherein said light beam incident on the sieving matrix is delivered through at least one optical coupling element located at at least one of the edges of the waveguide and said light beam delivered though said optical coupling element is collimated by a collimator located before the first waveguiding unit.

35. An electrophoresis apparatus according to claim 34, wherein said at least one optical coupling element is an optical fiber element.

36. An electrophoresis apparatus according to claim 34 or 35, wherein said collimator is a convex-shaped lens.

37. An electrophoresis apparatus according to any one of claims 23 to 36, wherein both plates of said two-plate housing are made of a plastic material.

38. An electrophoresis apparatus according to any one of claims 23 to 36, wherein said cover plate is made of glass.

39. An electrophoresis apparatus according to any one of claims 23 to 38, wherein said two-plate housing comprises a precast sieving matrix.

40. An electrophoresis apparatus according to claim 39, wherein said precast sieving matrix is a precast gel which is transparent with respect to said incident light beams.

41. An electrophoresis apparatus according to claim 40, wherein said gel is polyacrylamide or a derivative thereof.

42. An electrophoresis apparatus according to any one of claims 23 to 41, further comprising at least one light source.

43. An electrophoresis apparatus according to claim 42, wherein said at least one light source comprises means for generating a plurality of light beams.

44. An electrophoresis apparatus according to claim 43, wherein said plurality of said light beams are modulated such as to prevent temporal overlapping between each said light beam.

45. An electrophoresis apparatus according to claim 43 or 44, wherein said plurality of said light beams are coupled by suitable means to a shared light radiation outlet means for emitting in turn each one of said plurality of said light beams.

46. An electrophoresis apparatus according to any one of claims 43 to 45, wherein each one of said plurality of said light beams is of a substantially different wavelength.

47. An electrophoresis apparatus according to any one of claims 42 to 46, wherein said at least one light source is a laser source.

48. An electrophoresis apparatus according to any one of claims 23 to 47, further comprising at least one light detector.

49. An electrophoresis apparatus according to claim 48, wherein said at least one light detector enables detection of fluorescence photons or variations of laser intensity.

50. An electrophoresis apparatus according to claim 49, wherein said at least one light detector is a charge coupled device (CCD) sensitive for the detection of fluorescence, a photodiode or a photomultiplier.

51. An electrophoresis apparatus according to any one of claims 23 to 50, further comprising means for processing the data obtained during the electrophoresis.

52. An electrophoresis apparatus according to any one of claims 23 to 50, wherein said electrophoretic chamber contains a sole two-plate housing,

53. An electrophoresis apparatus according to any one of claims 23 to 50, wherein said electrophoretic chamber contains a plurality of said two-plate housings in substantial parallel arrangement stacked along a third direction substantially orthogonal both to a first direction corresponding to the direction of migration of the at least one sample and to a second direction corresponding to the direction of propagation of said light beam.