Capillary electrophoresis apparatus

• US 5,045,172 A
• Filed: 11/14/1988
• Issued: 09/03/1991
• Est. Priority Date: 11/25/1987
• Status: Expired due to Term

• Current Assignee: Princeton Biochemicals, Inc.
• Original Assignee: Princeton Biochemicals, Inc.
• Inventors: Guzman, Norberto
• Primary Examiner(s): Niebling, John F.
• Assistant Examiner(s): Starsiak, Jr., John S.
• Application Number:
  US07/270,788
• Time in Patent Office: 1,023 Days
• Field of Search: 204/299 R, 204/180.1, 204/183.3, 73/864.23, 73/864.18, 73/863.01, 73/864.24, 73/864.25, 422/64
• US Class Current: 204/452
• CPC Class Codes: G01N 27/44704 Details; Accessories
• CPC Class Codes: G01N 27/44756 Apparatus specially adapted therefor
• CPC Class Codes: G01N 27/44782 of a plurality of samples

Abstract

The apparatus includes a capillary tube having input and output ends and having a detector coupled thereto. A rotatable table is provided at each end of the capillary tube and each table includes sample cups for containing samples to be analyzed, and, if desired, a medium to be introduced into the capillary for transporting a sample substance to be analyzed. An electrode is provided adjacent to each end of the capillary tube for applying electrical potential across the capillary tube to cause charged particles of a sample to flow through the capillary tube and past said detector which detects the components of the sample.

Electronic means, including a computer, are provided for causing various portions of the apparatus to operate automatically when performing an analytical operation.

Claims

1. Capillary electrophoresis apparatus comprising a capillary tube of the type which can be electrically charged, said capillary tube having first and second ends,

first means at said first end of said capillary tube providing a source of buffer solution and a source of a sample substance to be analyzed,

second means coupled to said apparatus for applying electrical potential across said capillary tube whereby a sample flows through said capillary tube and past a detector,

said first means includes a rotatable table carrying a plurality of sample cups and a holder for holding an end of said capillary tube in operative relation with one of the said cups, said cups containing either buffer solution or a sample to be analyzed, and

a T-shaped section of capillary tube inserted in said capillary tube and coupled to a source of cleaning fluid usable to clean said capillary tube.

2. The apparatus defined in claim 1 and including a removable coiled capillary cartridge coupled to said capillary tube.

3. The apparatus defined in claim 1 wherein said capillary tube comprises a plurality of sections coupled together end to end, the internal surfaces of said sections coated with different chemicals.

4. The apparatus defined in claim 3 wherein said chemicals serve to modify the flow of sample material along a capillary tube.

5. The apparatus defined in claim 3 wherein the adjacent ends of said sections are butted together and are secured together by means of surrounding a sleeve which is secured to outer surfaces of said capillary sections.

6. The apparatus defined in claim 1 and including a source of an inert gas coupled to said rotatable table for addition to sample cups therein.

7. The apparatus defined in claim 1 and including a detector coupled to the output end of said capillary tube for detecting the passage of sample therethrough.

8. Capillary electrophoresis apparatus comprising a capillary tube of the type which can be electrically charged, said capillary tube having first and second ends,

first means at said first end of said capillary tube providing a source of buffer solution and a source of a sample substance to be analyzed,

second means coupled to said apparatus for applying electrical potential across said capillary tube whereby a sample flows through said capillary tube and past said detector,

said first means includes a rotatable table carrying a plurality of sample cups and a holder for holding an end of said capillary tube in operative relation with one of the said cups, said cups containing either buffer solution or a sample to be analyzed,

said table including an annular array of holes in which sample cups are seated,

said holder being disposed so that said first end of said capillary tube is always positioned over one of said sample cups,

said holder including a cylindrical portion which has an aperture which is adapted to receive said first end of said capillary tube and said holder further has a hollow tubular portion which extends downwardly from said cylindrical portion and is adapted to be inserted into a sample cup,

said holder having a second aperture to receive an electrode,

third means at said second end of said capillary tube including a rotatable table and a plurality of second sample cups carried thereby, a second holder for holding said second end of said capillary tube in operative relation with one of said second sample cups,

a first electrode in operative relation with said first end of said capillary tube and a second electrode in operative relation with said second end of said capillary tube, and means for applying electrical potential between said first and second electrodes,

said electrical potential being applied with said first and second ends of said capillary tube seated in buffer solution,

a vertical post disposed adjacent to said holder and having a slot in its side wall,

a vertical rod inside said vertical post and adapted to move vertically up and down,

a horizontal arm extending laterally from said vertical rod through said slot,

a first electrode on the outer wall of said vertical rod,

a lead extending from said first electrode along said horizontal arm into said second aperture in said holder and into said hollow tubular portion, and

a second electrode disposed within said vertical post and including a lead coupled to a power supply,

said first electrode and said second electrode being positioned so that when said vertical rod moves a predetermined distance, said first and second electrodes make contact with each other.

9. The apparatus defined in claim 8 wherein first electrode is a film electrode.

10. The apparatus defined in claim 8 wherein said capillary tube having an inside diameter in the range of 25 microns to about 200 microns.

11. The apparatus defined in claim 8 and including table drive means for rotating said table with respect to said holder.

12. The apparatus defined in claim 11 and including electronic circuit for automatically synchronizing the operation of said holder drive means and said table drive means so that in a sequence of operations, said holder is raised above said table and then said table is rotated to a position where a selected cup is beneath said holder, and then said holder is lowered so that said first end of said capillary tube is in said cup.

13. Capillary electrophoresis apparatus comprising a capillary tube of the type which can be electrically charged, said capillary tube having first and second ends,

first means at said first end of said capillary tube providing a source of buffer solution and a source of a sample substance to be analyzed,

second means coupled to said apparatus for applying electrical potential across said capillary tube whereby a sample flows through said capillary tube and past said detector,

said first means includes a rotatable table carrying a plurality of sample cups and a holder for holding an end of said capillary tube in operative relation with one of the said cups, said cups containing either buffer solution or a sample to be analyzed, and

said second means includes a second rotatable table carrying a plurality of sample cups and a second holder for holding the other end of said capillary tube, and

means for varying the spacing between said first and second holders and the operating length of the capillary tube therebetween.

14. An automated capillary electrophoresis system including

a computer for controlling the operation of the system as an electrophoresis system,

a bus connected to said a computer,

a capillary tube for receiving a sample of a substance to be analyzed and having an input end and an output end, PG,47

a detector adjacent to said capillary tube for detecting the passage of elements of said sample to be analyzed thereby,

a first electorde at said input end of said capillary tube and in operative relation therewith and with fluids contained therein,

a second electrode at said output end of said capillary tube and in operative relation therewith and with fluids contained therein,

a power supply having terminals adapted to provide a plurality of output voltages, said terminals being coupled to said electrodes for applying voltages therebetween,

said power supply also being connected to said bus and to said computer whereby its operation and the application of selected voltages to said electrodes can be controlled and sequenced,

a timer control coupled to said bus and to said computer for controlling the time duration of the application of operating voltages to said electrodes by said power supply,

a first holder for said input end of said capillary tube,

a second holder for said output end of said capillary tube,

first holder drive means coupled mechanically to said first holder for driving said first holder and said input end of said capillary tube vertically up and down, said first holder drive means being electrically coupled to said bus and to said computer whereby the operation thereof can be automatically controlled,

first holder drive sensor means in operative relation with said first holder drive means for controlling the movement thereof,

second holder drive means coupled mechanically to said second holder for driving said second holder and said output end of said capillary tube vertically up and down, said second holder drive being electrically coupled to said bus and to said computer whereby the operation thereof can be automatically controlled,

second holder drive sensor means in operative relation with said second holder drive means controlling the up and down movement thereof,

a first rotatable table adjacent to said first holder and carrying cups positioned to receive said input end of said capillary tube,

a second rotatable adjacent to said second holder and carrying cups positioned to receive said output end of said capillary tube,

a first table drive means coupled mechanically to said first rotary table and electronically to said bus and to said computer,

first table drive sensor means associated with said first table drive means to control the operation thereof,

a second table drive means coupled mechanically to said second rotary table and electrically to said bus and to said computer,

second table drive sensor means assoaciated with said second table drive means to control the operation thereof,

a clock control means in said computer,

said computer operating to:

15. turn on said first and second holder drive means to raise said first and second holders a predetermined amount which raises said first and second holders above said first and second rotary tables respectively,turn on said first and second table drive means to rotate said first and second tables to a starting position under the control of said first and second table drive sensor means,turn on said first and second holder drive means to lower said first and second holders an amount determined by said first and second holder drive sensor means which places said holders and said input end of said capillary tube, which is filled with buffer solution, in a first cup containing a sample substance to be analyzed,cause a sample fluid to be injected into said capillary tube;

and

5. cause said sample to flow along said capillary tube.

17. The apparatus defined in claim 15 wherein said rotatable table is supported on a vertical post which extends below the top wall of said support member and includes a lower post portion thereat,

a motor coupled to said lower post portion beneath said top wall of said support member,

a horizontal sensor disk secured to said lower post portion and adapted to be rotated thereby, and

an optical sensor coupled to said horizontal disk and adapted to operate said motor in response to the position of said sensor disk with respect to said sensor.

19. The apparatus defined in claim 15 and including power interlock means associated with the covers of said boxes for disconnecting electrical power when a cover is removed.

20. The apparatus defined in claim 15 and including a first hollow, tubular vertical post having a slot in its wall with said vertically moveable first post disposed therewithin,

a first horizontal arm extending from said vertically moveable first post through said slot and carrying said first hollow tube at its outer end

said vertically moveable first post having a lower post portion extending downwardly through the base member of said first box to beneath said top wall of said support member,

a first motor coupled to said lower post position to drive it up and down,

a first optical sensor positioned adjacent to said lower post position,

a first means carried on said lower post position and positioned to operate with said first optical sensor to contorl the operation of said first motor,

a second hollow tubular vertical post having a slot in its wall with said vertically moveable second post disposed therewithin,

a second horizontal arm extending from said vertically moveable second post carrying said second hollow tube at its outer end, said vertically moveable second post having a lower portion extending downwardly through the base member of said second box to beneath said top wall of said support member,

a second motor coupled to said lower post portion of said vertically moveable second arm to drive it up and down,

a second optical sensor positioned adjacent to said lower post portion of said vertically moveable second arm, and

a second means carried on said lower post portion of said vertically moveable second arm and positioned to operate with said second optical sensor to control the operation of said second motor.

22. The apparatus defined in claim 20 wherein said last-named means includes

a first rotatable wheel and a second rotatable wheel spaced from said first rotatable wheel,

a drive belt coupled to said rotatable wheels,

a drive motor coupled to said first rotatable wheel, and

means coupled to said belt and said second box whereby operation of said drive motor and movement of said drive belt cause said second box to slide along said top wall to assure different spacings from said first box.

16. Capillary electrophoresis apparatus comprising a box-like support member having a top wall, front and rear walls and left and right end walls,

a first box enclosure at one end of said support member,

a second box enclosure at the opposite end of said support member,

said box enclosures each including a base member, left and right sidewalls, front and rear walls and a removable cover,

a first rotatable table disposed within said first box enclosure and rotatably supported on the base member thereof,

a plurality of apertures in said first table and a sample cup seated in each of said apertures,

a vertically moveable first post disposed adjacent to said first table and including a first hollow tube extending downwardly therefrom over said apertures in said first table, said first hollow being adapted to be moved into and out of a sample cup when said first arm moves down and up,

a first electrode extending into said first hollow tube,

a second rotatable table disposed within said second box enclosure and rotatably supported on the base member thereof,

a plurality of apertures in said second table and a sample cup seated in each of said apertures,

a vertically moveable second post disposed adjacent to said second table and including a second hollow tube extending downwardly therefrom over said apertures in said second table,

said hollow tube being adapted to be moved into and out of a sample cup when said second arm moves down and up,

a second electrode extending into said second hollow tube,

said first and second electrodes being adapted to have electrical power coupled thereto,

a capillary tube extending from said first box enclosure to said second box enclosure and having one end disposed within said first tube and the other end of said capillary tube disposed within said second hollow tube,

a detector disposed adjacent to said capillary tube for detecting the passage of charged particles therethrough, and

a pump coupled to the output end of said capillary tube, said pump comprising a miniature pump mounted inside said housing.

18. The apparatus defined in claim 16 wherein said motor is supported on the lower surface of said top wall of said support member.

21. Capillary electrophoresis apparatus comprising a box-like support member having a top wall, front and rear walls and left and right end walls,

said top wall having a top surface and a bottom surface,

a first box enclosure at one end of said support member,

a second box enclosure at the opposite end of said support member,

said box enclosures each including a base member, left and right sidewalls, front and rear walls and a removable cover,

an aperture in said top wall of said box-like support member, said aperture extending along a portion of the length at said top wall,

a first rotatable table disposed within said first box enclosure and rotatably supported on the base member thereof,

a plurality of apertures in said first table and a sample cup seated in each of said apertures,

a second rotatable table disposed within said second box enclosure and rotatably supported on the base member thereof,

a plurality of apertures in said second table and a sample cup seated in each of said apertures,

a capillary tube extending from said first box enclosure to said second box enclosure and having one end disposed in operative relation with said first table and the other end of said capillary tube disposed in operative relation with said second table, and

a detector disposed adjacent to said capillary tube for detecting the passage of charged particles therethrough,

said first box being mounted on said top wall,

said second box being slidably mounted on said top wall and secured to mounting means disposed beneath said top wall and within said box-like support member.

23. The apparatus defined in claim 21 and including a bellowtype screen disposed along said aperture in said top wall to prevent foreign objects from falling into said box-like support member.

24. Capillary electrophoresis apparatus comprising a box-like support member having a top wall, front and rear walls, and left and right end walls,

said top wall having a top surface and a bottom surface,

a first box enclosure at one end of said top wall of said support member,

a second box enclosure at the opposite end of said top wall of said support member,

means supporting a capillary tube between said first box and said second box, and

means associated with said box-like support member for varying the spacing between said first box and said second box whereby capillary tubes of different lengths can be supported therebetween.

26. The apparatus defined in claim 24 wherein said magnifying glass permits observation of the sample meniscus in said capillary tube to determine electroosmotic flow therein.

27. The apparatus defined in claim 24 wherein said magnifying glass permits observation of the sample meniscus in said capillary tube to determine osmotic flow therein.

29. The apparatus defined in claim 27 wherein said gas is a gas selected from the group of gases including helium, nitrogen and argon.

25. Capillary electrophoresis apparatus comprising a capillary tube of the type which can be electrically charged, said capillary tube having first and second ends,

first means at said first end of said capillary tube providing a source of buffer solution and a source of a sample substance to be analyzed,

second means coupled to said apparatus for applying electrical potential across said capillary tube whereby a sample flows through said capillary tube and past said detector,

said first means includes a rotatable table carrying a plurality of sample cups and a holder for holding an end of said capillary tube in operative relation with one of the said cups, said cups containing either buffer solutions or a sample to be analyzed,

a magnifying glass coupled to said capillary tube for viewing the flow of fluid through said capillary tube, and

a pump coupled to the output end of said capillary tube.

28. Capillary electrophoresis apparatus comprising a capillary tube of the type which can be electrically charged, said capillary tube having first and second ends,

first means at said first end of said capillary tube providing a source of buffer solution and a source of a sample substance to be analyzed,

second means coupled to said apparatus for applying electrical potential across said capillary tube whereby a sample flows through said capillary tube and past said detector,

said first means includes a rotatable table carrying a plurality of sample cups and a holder for holding an end of said capillary tube in operative relation with one of the said cups, said cups containing either buffer solution or a sample to be analyzed, and

a source of an oxygen absorbent gas coupled to said rotatable table for introduction of said gas into sample cups to remove air bubbles therefrom.

30. Capillary electrophoresis apparatus comprising a capillary tube of the type which can be electrically charged, said capillary tube having first and second ends,

first means at said first end of said capillary tube providing a source of buffer solution and a source of a sample substance to be analyzed,

second means coupled to said apparatus for applying electrical potential across said capillary tube whereby a sample flows through said capillary tube and past said detector,

said first means includes a rotatable table carrying a plurality of sample cups and a holder for holding an end of said capillary tube in operative relation with one of the said cups, said cups containing either buffer solution or a sample to be analyzed, and

including means for operating said second means to cause said electrical potential to be cyclically reversed to cause said sample to move first in one direction and then in the opposite direction past said detector to provide a series of detector pulses for identification of the sample.

31. The method of detecting the nature of a sample of a substance by capillary electrophoresis comprising the steps of

passing a substance to be analyzed in one direction through a detector to obtain a pulse representative of the optical wavelength of said sample,

passing said substance in the opposite direction through said detector to obtain a second pulse representat0ve of the optical wavelength of said sample and,

continuing the process of passing said substance back and forth through said detector to obtain a series of pulses which combine to provide accurate identification of the sample.

32. Apparatus for analyzing a sample material comprising

a capillary tube

a detector adjacent to said capillary tube and adapted to provide an output detector pulse when a sample material passes along said capillary tube and through said detector,

a source of sample material at one end of said capillary tube to be passed down said tube to said detector,

electrical means connected across said capillary tube for causing said sample material to pass in a first direction along said capillary tube through said detector to provide a first detection pulse,

said electrical means being reversible to cause said sample material to flow in the reverse direction to said first direction to cause said sample material to pass through said detector to provide a second detector pulse, and

means for toggling said electrical means to cause said sample substance to pass back and forth through said detector and providing thereby multiple detector pulses.

33. Capillary electrophoresis apparatus comprising a capillary tube of the type which can be electrically charged, said capillary tube having first and second ends,

first means at said first end of said capillary tube providing a source of buffer solution and a source of a sample substance to be analyzed,

second means coupled to said apparatus for applying electrical potential across said capillary tube whereby a sample flows through said capillary tube and past said detector,

said first means includes a rotatable table carrying a plurality of sample cups and a holder for holding an end of said capillary tube in operative relation with one of the said cups, said cups containing either buffer solution or a sample to be analyzed, and

said capillary tube is in the form of a coil of glass tubing.

35. The apparatus defined in claim 33 wherein the outlet end of said auxiliary tube is positioned over a rotatable table, for receiving samples from said auxiliary tube.

34. Capillary electrophoresis apparatus including a capillary tube having an inlet end and an outlet end for receiving a sample to be identified and for passing the sample along the length of the capillary,

a porous glass tube receiving the outlet end of said capillary tube and

an auxiliary tube in said porous glass tube having one end adjacent to the outlet end of said capillary tube and adapted to receive a sample from said capillary tube, said auxiliary tube having an outlet end from which the sample exits to a collection means.

36. The apparatus defined in claim 34 and including a sensor at the outlet end of said auxiliary tube, an optical glass fiber coupled at one end to said sensor and at the other end to a detector for detecting the passage of a sample through said auxiliary tube whereby rotation of said rotatable table may be effected as each sample appear.

37. Capillary electrophoresis apparatus comprising

a capillary tube of the type which can be electrically charged, said capillary tube having first and second ends,

first means at said first end of said capillary tube providing a source of buffer solution and a source of a sample substance to be analyzed,

second means coupled to said apparatus for applying electrical potential across said capillary tube whereby a sample flows through said capillary tube and past a detector,

said first means including a rotatable table carrying a plurality of sample cups and a holder for holding anend of said capillary tube in operativerelation with one of said cups, said cups containing either buffer solution or a sample to be analyzed, and

a plurality of chemical substances spaced apart along the length of said capillary tube, each of said chemical substances having a specific action with respect to constituent molecules contained within a sample flowing along said capillary and either attracting a molucule for later elution or permitting a molecule to pass along the capillary tube.

39. The apparatus defined in claim 37 wherein said chemical substances are in the form of coatings on the wall of said capillary tube.

40. The apparatus defined in claim 37 wherein said chemical substances are in bulk form and disposed within said capillary tube.

41. The apparatus defined in claim 39 wherein said chemical substances are coated on globules of insulating material.

38. Capillary electrophoresis apparatus comprising

a capillary tube of the type which can be electrically charged, said capillary tube having first and second ends,

first means at said first end of said capillary tube providing a source of buffer solution and a source of a sample substance to be analyzed,

second means coupled to said apparatus for applying electrical potential across said capillary tube whereby a sample flows through said capillary tube and past a detector, and

a plurality of chemical substances spaced apart along the length of said capillary tube, each of said chemical substances having a specific action with respect to constituent molecules contained within a sample flowing along said capillary and either attracting a molucule for later elution or permitting a molecule to pass along the capillary tube.