Capillary, interface and holder

• US 5,858,194 A
• Filed: 07/18/1996
• Issued: 01/12/1999
• Est. Priority Date: 07/18/1996
• Status: Expired due to Fees

• Current Assignee: Beckman Instruments, Inc. (Danaher Corporation)
• Original Assignee: Beckman Instruments, Inc. (Danaher Corporation)
• Inventors: Bell, Michael L.
• Primary Examiner(s): Warden, Robert
• Assistant Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US08/678,428
• Time in Patent Office: 908 Days
• Field of Search: 138/115, 210/321.75, 210/321.84, 210/445, 210/455, 347/65, 347/71, 204/450, 204/601, 204/518, 7/451, 7/600, 7/100, 7/101, 7/102, 7/104, 422/99, 422/81, 216/2, 29/890.1
• US Class Current: 204/601
• CPC Class Codes: G01N 27/44743 Introducing samples
• CPC Class Codes: G01N 27/44791 Microapparatus sample containers with integrated microfluidic structures B01L3/5027

Abstract

A capillary, interface and holder for a capillary electrophoresis system are provided herein. The capillary is disposed in a substantially planar housing having side surfaces. The capillary includes at least two, substantially coplanar capillary openings which extend through an interface surface located on one of the side surfaces. The interface includes at least two spaced apart receptacles for receiving an ionic fluid. Each receptacle includes a liquid permeable medium having a capillary area and a conductor area. Each capillary area is in fluid communication with one of the capillary openings and each conductor area is in contact with at least one electrical conductor. At least two of the capillary areas are substantially coplanar. The ionic fluid is disposed in each receptacle to create an electrical path between the capillary area and conductor area of each receptacle. The holder selectively retains the housing and the interface so that the capillary areas contact the capillary openings and the conductor areas contact the electrical conductors.

Claims

1. A device for analysis of a fluid, the device comprising:

(a) a substantially planar, substantially transparent housing having an interface surface which is located on an external side of the housing; and

(b) a channel disposed within the housing, the channel being adapted for transporting the fluid during chemical analysis, the channel having a substantially constant cross-sectional area throughout the length of the channel;

wherein the channel includes at least one capillary opening which extends through the interface surface of the housing.

2. The device of claim 1 further including a plurality of capillary openings, at least two of the capillary openings being substantially coplanar.

3. The device of claim 1 wherein the housing comprises (i) a substantially planar channel plate having an interface surface and an upper surface and (ii) a substantially planar cover plate sealed over the upper surface of the channel plate with an interface surface of the cover plate substantially aligned and substantially coplanar with the interface surface of the channel plate.

4. A capillary electrophoretic system comprising:

(a) the device of claim 1;

(b) an electrical conductor; and

(c) an interface adapted for electrically connecting the capillary opening and the electrical conductor, the interface contacting the capillary opening and being in fluid communication with the capillary opening.

5. The device of claim 1 wherein the channel has a cross-sectional area of between approximately one hundred to five thousand micrometers squared.

6. A capillary electrophoretic system comprising:

(a) a device comprising (i) a channel disposed in a substantially planar housing having an interface surface, and (ii) at least two capillary openings in fluid communication with the channel which extend through the interface surface of the housing;

(b) at least two electrical conductors; and

(c) an interface comprising at least two receptacles for receiving an ionic fluid, each receptacle having a capillary area and a conductor area separated by a liquid permeable medium, the liquid permeable medium including a plurality of pores which are adapted to retain a portion of the ionic fluid, the receptacles being spaced apart from each other a sufficient distance so that the capillary area of each receptacle is connected in fluid communication with one of the capillary openings and the receptacles being positioned so that at least two of the capillary areas are substantially coplanar;

wherein an electrical path is established between the capillary area and conductor area of each receptacle without establishing an electrical path between at least two of the receptacles.

7. The capillary electrophoretic system of claim 6 wherein at least two of the receptacles comprise a continuous piece of liquid permeable medium which substantially inhibits the flow of liquid laterally between at least two of the receptacles, wherein the liquid permeable medium includes a plurality of pores.

8. The capillary electrophoretic system of claim 6 comprising an inhibitor for substantially inhibiting the flow of ionic fluid between at least two of the receptacles.

9. The capillary electrophoretic system of claim 8 wherein the inhibitor is an area between at least two receptacles which does not contain a liquid permeable medium having pores.

10. The capillary electrophoretic system of claim 8 wherein the inhibitor is a substantially hydrophobic barrier disposed in a liquid permeable medium between at least two receptacles.

11. The capillary electrophoretic system of claim 8 wherein each receptacle comprises an individual piece of liquid permeable medium having pores and the inhibitor comprises an area between at least two of the receptacles which does not contain a liquid permeable medium having pores.

12. The capillary electrophoretic system of claim 8 wherein at least two of the receptacles comprises an interconnected piece of liquid permeable medium having pores and the inhibitor comprises a substantially hydrophobic barrier disposed between at least two of the receptacles.

13. The capillary electrophoretic system of claim 6 wherein the housing is substantially transparent and includes a front surface which is substantially perpendicular to the interface surface and wherein, the channel is substantially parallel to the front surface of the housing and is adapted for transporting a fluid during capillary electrophoresis.

14. A method for making a device which is useful for an analysis of a fluid, the method comprising the steps of:

(a) forming a channel in an upper surface of a substantially planar, substantially transparent channel plate, the channel being adapted for transporting a fluid during capillary electrophoresis and having at least two, substantially coplanar capillary openings which extend through an external interface surface of the channel plate, the interface surface being substantially perpendicular to the upper surface, the channel having a substantially constant cross-sectional area throughout the length of the channel; and

(b) substantially sealing a substantially planar, substantially transparent cover plate over the upper surface of the channel plate.

15. The method of claim 14 wherein the step of substantially sealing the cover plate over the upper surface of the channel plate includes the step of substantially aligning the interface surface of the channel plate with an interface surface of the cover plate so that the interface surface of the cover plate and the interface surface of the channel plate are substantially coplanar.

16. The method of claim 14 wherein the step of forming a channel includes the step of forming a channel having a cross-sectional area of between approximately one hundred to five thousand micrometers squared.

17. A device for capillary electrophoresis, the device comprising:

a substantially planar housing having an interface surface which is located on a side of the housing; and

a capillary disposed in the housing, the capillary including two interconnected channels, each of the channels including a capillary opening which extends through the interface surface of the housing, each channel having a substantially constant cross-sectional area throughout the length of each channel.

18. The device of claim 17 wherein the housing is substantially transparent and include a front surface which is substantially perpendicular to the interface surface, wherein, the plurality of channels extend substantially parallel to the front surface.

19. An interface adapted for electrically connecting first and second capillary openings in a housing, the interface comprising:

first and second receptacles, each of the receptacles including a capillary area, a conductor area and a liquid permeable medium which receives an ionic fluid for establishing a separate electrical path between the capillary area and the conductor area for each receptacle, the liquid permeable medium having a plurality of pores which are adapted to retain a portion of the ionic fluid, the receptacles being spaced apart from each other a sufficient distance so that the capillary area of each receptacle is adapted to be connected in fluid communication with one of the capillary openings.

20. The interface of claim 19 including an inhibitor for substantially inhibiting the flow of ionic fluid between the first and second receptacles, the first and second receptacles being positioned so that the capillary area of each receptacle is substantially coplanar.

21. The interface of claim 20 wherein the inhibitor is an area between the first and second receptacles which does not contain a liquid permeable medium having pores.

22. The interface of claim 20 wherein the inhibitor is an area between the first and second receptacles which does not contain a liquid permeable medium having pores.

23. The interface of claim 20 wherein the inhibitor is a substantially hydrophobic barrier disposed between the first and second receptacles.

24. The interface of claim 20 wherein each receptacle comprises an individual piece of liquid permeable medium and the inhibitor comprises an area between the first and second receptacles which does not contain a liquid permeable medium having pores.

25. The interface of claim 20 wherein the interface further comprises a support which secures the first and second receptacles together.

26. The interface of claim 25 wherein the support includes an interface aligner for aligning the capillary areas with the capillary openings.

27. The interface of claim 19 wherein at least one of the receptacles includes a fine pores area positioned proximate the capillary area and a coarse pores area.

28. A capillary electrophoretic system comprising:

(a) a device comprising (i) a channel disposed in a housing having an interface surface, the channel being adapted for transporting a fluid during capillary electrophoresis, and (ii) first and second capillary openings in fluid communication with the channel which extend through the interface surface of the housing;

(b) at least two electrical conductors; and

(c) the capillary interface of claim 19 electrically connecting each of the capillary openings to one of the electrical conductors.

29. The capillary electrophoretic system of claim 28 wherein the housing is substantially transparent and comprises (i) a substantially planar channel plate having an interface surface and an upper surface and (ii) a substantially planar cover plate sealed over the upper surface of the channel plate with an interface surface of the cover plate substantially aligned and substantially coplanar with the interface surface of the channel plate.

30. The capillary electrophoretic system of claim 28 wherein the capillary areas are adapted to be selectively moved into and out of fluid communication with the capillary openings.

31. The capillary electrophoretic system of claim 28 comprising a holder for selectively retaining the capillary areas in fluid communication with the capillary openings, the holder comprising (i) first and second members, spaced apart a sufficient distance to receive the housing and the interface therebetween and (ii) a pressure inducer adapted for pressing the interface surface of the housing and the interface together.

32. The capillary electrophoretic system of claim 28 wherein the capillary openings are spaced apart a distance which is substantially equal to "X" and the capillary areas are spaced apart a distance which is substantially equal to "X".

33. A capillary electrophoretic system comprising:

a device including (i) a substantially planar, substantially transparent housing having front surface and an interface surface and (ii) a channel extending substantially parallel to the front surface, the channel being adapted for transporting a fluid during capillary electrophoresis and including a capillary opening in fluid communication with the channel which extends through the interface surface of the housing;

an electrical conductor; and

an interface including receptacle having a capillary area which is in fluid communication with the capillary opening and a conductor area which contacts the electrical conductor, the receptacle including a liquid permeable medium having a plurality of pores which receive an ionic fluid to establish an electrical path between the capillary area and conductor area.

34. The capillary electrophoretic system of claim 33 including a holder having a pressure inducer which is adapted for pressing the interface surface of the housing and the interface together.

35. A capillary electrophoretic system comprising:

a device for the analysis of a fluid, the device comprising;

(i) a substantially planar, substantially transparent housing having an interface surface which is located on an external side of the housing;

(ii) a channel disposed within the housing, the channel being adapted for transporting the fluid during chemical analysis; and

(iii) at least one capillary opening in fluid communication with the channel which extends through the interface surface of the housing;

an electrical conductor; and

an interface adapted for electrically connecting the capillary opening and the electrical conductor, the interface comprising a first receptacle having a liquid permeable medium for receiving an ionic fluid, the liquid permeable medium including pores which are adapted to retain a portion of the ionic fluid.

36. The capillary electrophoretic system of claim 35 wherein the capillary includes a second capillary opening and the interface includes at least a second receptacle, the first and second receptacles each comprising (i) a liquid permeable medium having a plurality of pores which are adapted to retain a portion of the ionic fluid and (ii) the first and second receptacles each including a co-planar capillary area connected in fluid communication with one of the capillary openings.

37. The capillary electrophoretic system of claim 36, wherein the interface further comprising an inhibitor for inhibiting the flow of ionic fluid between the receptacles.

38. A capillary electrophoretic system comprising:

a device for the analysis of a fluid, the device comprising;

(i) a substantially planar, substantially transparent housing having an interface surface which is located on an external side of the housing;

(ii) a channel disposed within the housing, the channel being adapted for transporting the fluid during chemical analysis; and

(iii) at least one capillary opening in fluid communication with the channel which extends through the interface surface of the housing;

an electrical conductor;

an interface adapted for electrically connecting the capillary opening and the electrical conductor; and

a holder for selectively retaining the interface in fluid communication with the capillary opening, the holder comprising (i) first and second members, spaced apart a sufficient distance to receive the housing and the interface therebetween and (ii) a pressure-inducer positioned between the first and second members which expands a sufficient distance to press the interface surface of the housing and the interface together.