Flow cytometry

• US 4,673,288 A
• Filed: 09/07/1984
• Issued: 06/16/1987
• Est. Priority Date: 05/15/1981
• Status: Expired due to Fees

• Current Assignee: Ratcom
• Original Assignee: Ratcom
• Inventors: Eggleston, Ross W., Thomas, Richard A.
• Primary Examiner(s): McGraw, Vincent P.
• Application Number:
  US06/648,356
• Time in Patent Office: 1,012 Days
• Field of Search: 356/72, 356/73, 356/246, 356/39, 324/71.1, 324/71.4
• US Class Current: 356/72
• CPC Class Codes: G01N 15/13 Details pertaining to apertures
• CPC Class Codes: G01N 15/1404 Handling flow, e.g. hydrodynamic focusing
• CPC Class Codes: G01N 2015/1019 Associating Coulter-counter and optical flow cytometer [OFC]
• CPC Class Codes: G01N 2015/1415 Control of particle position
• CPC Class Codes: G01N 2015/1477 Multiparameters

Abstract

A flow cytometer has an aperture in which an inlet chamber and/or an outlet chamber have predetermined geometric relationships with respect to the aperture for decreasing electronic edge effects and increasing the sensitivity of electronic particle volume measurements. In one embodiment, the aperture is triangular and is formed by assembling a plurality of truncated pyramids with their truncated surfaces defining aperture walls. At least one of the elements forming the aperture walls is either part of a lens system or a transparent cover plate so that simultaneous optical and electronic cell volume measurements can be performed. On one embodiment, a piezoelectric transducer is provided to sonically clear any aperture clogging.

Claims

1. A flow transducer comprising means defining an aperture having an axis, said aperture having at least one flat side, means defining an inlet chamber and an outlet chamber immediately adjacent the aperture along its axis, said inlet and outlet chambers having walls disposed at an angle of at least 5°

relative to the plane of the aperture, said inlet and outlet chambers at a distance from the aperture of twice the width of the aperture in a plane through its axis having cross-sectional areas at least 10 times the cross-sectional area of said aperture.

2. A transducer for a flow cytometer in accordance with claim 1 wherein said transducer is formed of a plurality of solid polygons joined such that adjacent flat surfaces of said polygons define walls of the aperture for the flow cytometer, and others of the surfaces of said polygons define said inlet and outlet chambers.

3. A transducer in accordance with claim 2 wherein said solid polygons are truncated pyramids, and in which said aperture is a triangular cross section aperture.

4. A transducer in accordance with claim 2 including means for introducing a sheath of carrier fluid into said inlet chamber, a sample injector for injecting sample particles in said sheath of carrier fluid, said sample injector being positioned at an angle with respect to said sheath of carrier fluid, and means for adjusting said sample injector to selectively inject the sample into different regions of the flow sheath to control the position of the sample stream in the aperture.

5. A transducer in accordance with claim 2 including piezoelectric crystal means, and means for actuating said piezoelectric crystal means to vibrate materials present in the aperture for clearing clogs.

17. A transducer for a flow cytometer in accordance with claim 1 wherein said aperture has a triangular cross section.

6. A flow cytometer for making simultaneous electronic and optical measurements on a particle flowing through a sensing zone thereof, comprising a transducer formed of a plurality of solid polygons joined such that adjacent flat surfaces of said polygons define a polygonal aperture at the sensing zone and other surfaces of said polygons define inlet and outlet chambers to said aperture having a predefined geometric relation to said aperture, said inlet and outlet chambers defining an arch shaped fluid passageway with the aperture at the arch vertex, means for establishing a flow of electrolyte through said aperture, said inlet and outlet chambers being configured to establish laminar flow of said electrolyte through said aperture, injector means for injecting samples of particles into said laminar flow of electrolyte, one or more electrodes coupled to said inlet chamber and one or more electrode coupled to said outlet chamber, means for establishing a current flow through said aperture between said electrodes, monitoring means for monitoring the electrical current flow through said aperture, at least one of the solid polygons defining said aperture being an element in an optical measurement system, said system including means for introducing exciting light through said at least one solid polygon into said aperture, and means for collecting light from a sample particle in said aperture.

7. A flow cytometer in accordance with claim 6 wherein said solid polygons are truncated pyramids, with the truncated surfaces forming walls of said aperture, and in which said polygonal aperture cross section is a triangle.

8. A flow cytometer in accordance with claim 6 wherein two solid polygons are provided in the form of truncated pyramids with their truncated surfaces forming two walls of a triangular aperture, and in which a flat cover plate is provided to form the third wall of the triangular aperture.

9. A flow cytometer in accordance with claim 6 including sonication means for establishing sonic vibration in the electrolyte for clearing clogs which may occur in said aperture.

10. A flow cytometer in accordance with claim 7 wherein sonication means is provided coupled to said injector means for establishing localized sonic vibration in electrolyte at and near said aperture.

11. A flow cytometer in accordance with any of claims 6 through 10, wherein a plurality of the elements forming walls of said aperture are portions of an optical system for collecting light from a sample particle in said aperture.

12. A flow cytometer in accordance with any of claims 6 through 10 wherein said exciting light is of a type to produce fluorescence in the sample particles, and wherein said means for collecting light collects the fluorescent light from the sample particle.

13. A flow cytometer in accordance with any of claims 6 through 10 wherein said means for collecting light comprises at least one optical detector positioned at a predetermined angle with respect to the exciting light, for detecting light scattered by the sample particle.

14. A flow cytometer in accordance with any of claims 6 through 10 wherein said means for collecting light includes at least one optical detector for detecting fluorescent light emitted by the particle and at least one additional optical detector positioned at a predetermined angle with respect to the exciting light, for detecting light scattered by the sample particle.

15. A flow cytometer in accordance with claim 6 wherein at least one of said solid polygons has a mirrored surface for reflecting light emitted by a sample particle through another of the elements defining the polygonal aperture.

16. A flow cytometer in accordance with claim 6 wherein the predetermined geometric relation between the inlet and outlet chambers and the aperture is such that walls of the inlet and outlet chambers join the aperture at an angle equal to at least 5°

with respect to the plane of the aperture, and in which at a distance in the inlet and outlet chambers from the aperture equal to twice the width of the aperture along any plane through its axis, the cross-sectional areas of the inlet and outlet chambers are at least ten times the cross-sectional area of the aperture.

18. A flow cytometer in accordance with claim 6 wherein at least one of said solid polygons has a mirror surface for reflecting exciting light onto a sample particle in said aperture.

19. A flow cytometer for making simultaneous electronic and optical measurements on a particle flowing through a sensing zone thereof, comprising a transducer formed of a plurality of solid polygons joined such that adjacent surfaces of said polygons define an aperture at the sensing zone and other surfaces of said polygons define inlet and outlet chambers to said aperture having a predefined geometric relation to said aperture, said inlet and outlet chambers defining an arch shaped fluid passageway with the aperture at the arch vertex, means for establishing a flow of electrolyte through said aperture, said inlet and outlet chambers being configured to establish laminar flow of said electrolyte through said aperture, injector means for injecting samples of particles into said laminar flow of electrolyte, one or more electrodes coupled to said inlet chamber and one or more electrodes coupled to said outlet chamber, means for establishing a current flow through said aperture between said electrodes, monitoring means for monitoring the electrical current flow through said aperture, at least one of the solid polygons defining said aperture being an element in an optical measurement system, said system including means for introducing exciting light through said at least one solid polygon into said aperture, and means for collecting light from a sample particle in said aperture.

20. In a flow transducer of the type including an inlet chamber and an outlet chamber separated by an aperture and also including means for establishing a flow of particles in a carrier through said aperture, the improvement comprising cavitation inducing means for introducing cavitation in the carrier for vibrating materials present in the aperture for clearing clogs.

21. A flow cytometer in accordance with claim 20 wherein said means for establishing a flow of particles through the aperture comprises means for establishing a flow of a carrier fluid through the aperture and a particle injector situated on the inlet chamber side of the aperture.

22. A flow cytometer in accordance with claim 21, wherein said sonication means comprises a piezoelectric crystal coupled to the particle injector for establishing localized sonic vibration in the carrier fluid at and near the aperture.

23. A flow transducer comprising means defining an aperture having an axis, means defining an inlet chamber and an outlet chamber immediately adjacent the aperture along its axis, said inlet and outlet chambers having walls disposed at an angle of at least 5°

relative to the plane of the aperture, said inlet and outlet chambers at a distance from the aperture of twice the width of the aperture in a plane through its axis having cross-sectional areas which are rotationally asymmetric with respect to the axis of the aperture and which are at least 10 times the cross-sectional area of said aperture.