Cytometer having fluid core stream position control

• US 20060023207A1
• Filed: 07/27/2004
• Published: 02/02/2006
• Est. Priority Date: 07/27/2004
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Fritz, Bernard S., Cox, James A.
• Granted Patent: US 7,242,474 B2
• Time in Patent Office: Days
• US Class Current: 356/246
• CPC Class Codes: G01N 15/1404 Handling flow, e.g. hydrodynamic focusing
• CPC Class Codes: Y10T 436/118339 with formation of a segmented stream

Abstract

A cytometer having two or more chambers or regions in a containment structure of sheathing fluid that may be used to provide hydrodynamic focusing of another fluid having particles to be observed. The latter fluid may be a core stream which may have its lateral position in a flow or measurement channel affected by control of at least one of the parameters of the several segments of the sheathing fluid. The lateral position of the core stream may be aligned with a light source and detector for a count and observation of the particles. Electrical signals from the detector may be fed back to a processor which may control one or more parameters of the sheathing fluid in the various chambers or regions via pumps, valves, and flow and pressure sensors. This control of parameters may provide for the positioning of the core stream. This cytometer may be miniaturized.

Claims

1. A cytometer system comprising:

a flow channel having an axis;

a hydrodynamic focusing channel connected to the flow channel;

an injection channel connected to the hydrodynamic focusing channel;

a first sheath fluid channel connected to the hydrodynamic focusing channel; and

a second sheath fluid channel connected to the hydrodynamic focusing channel;

2. The system of claim 1, further comprising:

a light source proximate to the flow channel; and

a detector proximate to the flow channel.

3. The system of claim 2, further comprising:

a first pressure control mechanism connected to the first sheath fluid channel; and

a second pressure control mechanism connected to the second sheath fluid channel.

4. The system of claim 3, further comprising a processor connected to the detector, the first pressure control mechanism and the second pressure control mechanism.

5. The system of claim 4, wherein:

the detector may provide a signal to the processor indicating a position of a core stream relative to the axis of the flow channel;

the first and second pressure mechanisms may affect an alignment of the core stream relative to the axis of the flow channel; and

the processor may provide signals to the first and second pressure mechanisms in response to a signal from the detector to effect the alignment of the core stream relative to the axis of the flow channel.

6. The system of claim 5, wherein the signals to the first and second pressure mechanisms in response to the signal from the detector may align the core stream with the axis of the flow channel.

7. A method of alignment for a cytometer, comprising:

providing a sample fluid;

providing a first sheath fluid proximate to the sample fluid;

providing a second sheath fluid proximate to the sample fluid; and

hydrodynamically focusing the sample fluid into a core stream with the first and second sheath fluids into a flow channel.

8. The method of claim 7, further comprising affecting the first and second sheath fluids proximate to the sample fluid to affect an alignment of the core stream relative to the flow channel.

9. The method of claim 8, further comprising differentially affecting flows of the first and sheath fluids to align the core stream with an axis of the flow channel.

10. The method of claim 9, further comprising determining the alignment of the core stream with a light source and detector proximate to the flow channel.

11. The method of claim 10, wherein:

the core stream comprises particles that may scatter light from the light source;

the detector detects the light scattered by the particles; and

a magnitude of scattered light by the particles is indicative of a position of the core stream with the axis of the flow channel.

12. A means for alignment in a cytometer, comprising:

means for providing a sample fluid;

means for providing a plurality of sheathing fluids;

means for hydrodynamically focusing the sample fluid into a core steam with the multitude of sheathing fluids; and

means for individually affecting the flows of the plurality the sheathing fluids to effect an amount of alignment of the core stream with an axis in a flow channel.

13. The means of claim 12, further comprising means for detecting the amount of alignment of the core steam with the axis in the flow channel.

14. The means of claim 13, further comprising means for providing information from the means for detecting the amount of alignment of the core stream to the means for individually affecting the flows of the plurality of the sheathing fluids to maintain an alignment of the core stream.

15. The means of claim 14, wherein:

the core stream comprises particles; and

the particles flow in a single file through the flow channel.

16. A fluid positioning system, comprising:

a hydrodynamic focusing region;

a plurality of sheathing fluid regions proximate to the hydrodynamic focusing region;

a core fluid region proximate to the hydrodynamic focusing region;

an illumination and detection region proximate to the hydrodynamic focusing region; and

a parameter controller proximate to each region of the plurality of sheathing fluid regions.

17. The system of claim 16, wherein a core fluid from the core fluid region is sheathed with a sheathing fluid from each region of the plurality of sheathing fluid regions into a core stream in the hydrodynamic focusing region.

18. The system of claim 17, wherein:

each sheathing fluid from each region of the plurality of regions has a parameter changeable by the parameter controller proximate to the respective region; and

the core stream has a position that is changeable by a variable parameter of at least one sheathing fluid.

19. The system of claim 18, wherein the core stream may be positioned in the illumination and detection region.

20. The system of claim 19, further comprising an interface connecting at least two parameter-controllers to the illumination and detection region for positioning the core stream in the illumination and detection region.