Fluorescence flow cytometry device and method

1. A microfluidic interrogation apparatus, comprising:

indexing structure effective to hold a microfluidic device at a position such that an interrogation aperture of said microfluidic device is urged to a desired location, said microfluidic device being of the type arranged to urge particles of interest through said interrogation aperture in a substantially single-file arrangement;

a source of stimulation radiation structured to propagate radiation in a particular direction;

adjustment structure configured to refine alignment of said interrogation aperture with respect to said radiation from an initial position to maximize beam propagation into said interrogation aperture;

sensor structure disposed to provide steering feedback to said adjustment structure; and

a first photodetector disposed to detect an identifying characteristic from a particle disposed inside said interrogation aperture.

2. The apparatus according to claim 1 , wherein:

said adjustment structure comprises steering structure configured to change the disposition of a path of propagation of said beam.

3. The apparatus according to claim 2 , wherein:

said steering structure comprises a mirror affixed to a steering table.

4. The apparatus according to claim 1 , wherein:

said adjustment structure comprises X-Y displacement structure configured to move said beam into alignment with said microfluidic device.

5. The apparatus according to claim 1 , wherein:

said adjustment structure comprises X-Y displacement structure configured to move said microfluidic device into alignment with said beam.

6. The apparatus according to claim 1 , wherein:

said sensor structure comprises an optical diode disposed on an exit side of said interrogation aperture with respect to said stimulation radiation.

7. The apparatus according to claim 1 , wherein:

said sensor structure comprises a photodetector disposed on an entrance side of said interrogation aperture with respect to said stimulation radiation.

8. The apparatus according to claim 1 , wherein:

said sensor structure comprises said first photodetector.

9. The apparatus according to claim 1 , wherein:

said adjustment structure comprises manual manipulation by a user of said apparatus.

10. The apparatus according to claim 1 , wherein:

said source of stimulation radiation comprises a laser directed through a focusing lens to form a coherent beam, said coherent beam having a characteristic cross-section size that is smaller than a characteristic size of a cooperating cross-section of said interrogation aperture.

11. The apparatus according to claim 10 , further comprising:

a restricting orifice disposed in a path of said beam and upstream of said aperture, said orifice being structured to resist passage of fringe radiation to improve coherence of said beam downstream of said orifice.

12. The apparatus according to claim 1 , wherein:

said indexing structure comprises a first pin structured for reception in a first socket of said microfluidic device, said first pin and said first socket cooperating to cause said first socket of an installed microfluidic device to be positioned at a known X-Y coordinate with respect to said apparatus.

13. The apparatus according to claim 12 , further comprising:

a second pin structured for reception in a second socket of said microfluidic device, said second pin and said second socket cooperating to cause said installed microfluidic device to be positioned at a known angular orientation with respect to said first pin.

14. The apparatus according to claim 1 , wherein:

said source of stimulation radiation comprises a laser directed through a focusing lens to form a coherent beam;

a steerable first mirror is disposed downstream of said lens to redirect said beam for reflection from a second mirror and into an interrogation aperture of an installed microfluidic device, said second mirror being a dichroic mirror; and

said apparatus is structured and arranged such that Stokes-shift emission radiation from a particle disposed in said interrogation aperture may propagate along an emission radiation path through said second mirror for detection by a first photodetector.

15. The apparatus according to claim 14 , further comprising:

a plurality of photodetectors, each such photodetector being associated with a mirror disposed in said emission radiation path and adapted to direct emission radiation from said emission radiation path toward a photodetector.

16. The apparatus according to claim 15 , further comprising:

a mirror element disposed upstream of said photodetectors and arranged to change a direction of propagation of said emission radiation path to permit compact assembly of said apparatus.

17. The apparatus according to claim 1 , wherein:

said source of stimulation radiation comprises a laser directed through a focusing lens to form a coherent beam, said beam being directed for propagation through a first dichroic mirror and into said interrogation aperture, said first dichroic mirror being structured and arranged such that Stokes-shift emission radiation from a particle disposed in said interrogation aperture may propagate along an emission radiation path for reflection from said first dichroic mirror and subsequent detection by a first photodetector.

18. The apparatus according to claim 17 , further comprising:

a plurality of photodetectors, each such photodetector being associated with a mirror disposed in said emission radiation path downstream from said first dichroic mirror and adapted to direct emission radiation from said emission radiation path toward a photodetector.

19. A method, comprising the steps of:

urging an interrogation aperture of a microfluidic device to a desired location, said microfluidic device being of the type arranged to urge particles of interest through an interrogation aperture in a substantially single-file arrangement;

emitting radiation oriented for propagation of radiation in a particular direction;

using steering feedback from a sensor structure, adjusting a relative position of said microfluidic device with respect to said beam to maximize beam propagation into said interrogation aperture;

processing a sample of particle-carrying fluid to detect an identifying characteristic from one or more particle of interest in said sample; and

removing said microfluidic device from its position near the desired location.

20. The method according to claim 19 , further comprising the steps of:

detecting Coulter effect phenomena due to travel of one or more particle of interest through said interrogation aperture; and

simultaneously detecting Coulter effect phenomena and Stokes-shift emission while processing said sample.