Particle analysis in an acoustic cytometer

1. An apparatus, comprising:

a flow channel configured for flowing a fluid containing therein a plurality of particles, each particle having at least one major axis; and

an acoustic signal producing transducer operable to give rise to an acoustic radiation pressure within the fluid disposed within the flow channel,

the acoustic radiation pressure being applied so as to rotate at least some of the particles such that the major axes of the at least some particles are parallel with one another.

2. The apparatus of claim 1 , further comprising a flow cytometer, the flow cytometer being in fluid communication with the flow channel.

3. The apparatus of claim 1 , further comprising a particle sorter in fluid communication with the flow channel.

4. The apparatus of claim 1 , further comprising a particle analyzer, the particle analyzer being in fluid communication with the flow channel.

5. The apparatus of claim 1 , further comprising an imager configured to image particles disposed within the flow channel.

6. A method, comprising:

to a fluid medium disposed in a flow channel,

the fluid medium having disposed therein at least some particles defining major axes,

applying acoustic radiation pressure to the fluid medium and the at least some particles so as to rotate the at least some particles such that the major axes of the at least some particles are parallel with one another.

7. The method of claim 6 , wherein the flow channel defines a major axis, and wherein the major axes of at least some of the particles are rotated such that the major axes are parallel with the major axis of the flow channel.

8. The method of claim 6 , wherein the at least some particles further define at least one minor axis, and wherein the acoustic radiation pressure is applied such that (1) the major axes of the at least some particles lie in a first force equilibrium plane; and (2) the minor axes of the at least some particles lie in a second force equilibrium plane that is perpendicular to the first force equilibrium plane.

9. The method of claim 6 , wherein the acoustic radiation pressure is applied such that the at least some of the particles are rotated such that the major axes of the at least some of the particles lie in a stable force equilibrium plane.

10. The method of claim 6 , further generating and collecting an optical scattering signature from the at least some particles disposed in the fluid medium and located at an interrogation zone, the optical signature being based on the alignment of the at least some particles in an optical scattering plane.

11. The method of claim 10 , further comprising selecting at least some of the particles on the basis of the optical scattering signature of the at least some particles.

12. The method of claim 10 , further comprising calibrating the optical scattering signature of a particle to a specific orientation of the particle.

13. The method of claim 6 , further comprising generating and collecting images of one or more of the at least some particles.

14. The method of claim 6 , further comprising generating and analyzing signal data associated with the at least some particles.

15. The method of claim 14 , wherein the analyzing comprises at least one of pulse shape analysis and angular scattering analysis.

16. The method of claim 6 , further comprising flowing the fluid medium to a flow cytometer.

17. A method, comprising:

to a fluid medium being disposed in a flow channel,

the fluid medium having disposed therein at least some particles, each of the at least some particles defining a major axis,

applying acoustic radiation pressure to the fluid medium and the at least some particles so as to rotate the at least some particles; and

(1) generating and collecting optical scattering data of the at least some rotated particles, (2) generating and collecting one or more images of the at least some rotated particles, or both (1) and (2).

18. The method of claim 17 , further comprising discriminating between two particles based on optical scattering signature data of the two particles.

19. The method of claim 17 , further comprising isolating a contribution of a rotated particle of the at least some rotated particles to optical scattering data of the at least some rotated particles by utilizing the solution of the inverse scattering problem for contacting spheres.

20. The method of claim 17 , further comprising communicating the at least some rotated particles to an analyzer in fluid communication with the flow channel.