Flow cytometer

• US 6,713,019 B2
• Filed: 03/27/2002
• Issued: 03/30/2004
• Est. Priority Date: 03/29/2001
• Status: Active Grant

• Current Assignee: Sysmex Corporation
• Original Assignee: Sysmex Corporation
• Inventors: Ozasa, Masatsugu, Kosako, Tatsuya
• Primary Examiner(s): Wallenhorst, Maureen M.
• Application Number:
  US10/106,062
• Publication Number:
  US 20020141902A1
• Time in Patent Office: 734 Days
• Field of Search: 436/10, 436/63, 436/52, 436/164, 436/165, 436/172, 422/73, 422/81, 422/82.05, 422/82.08, 422/82.09, 356/317, 356/318, 356/336, 356/337, 356/338
• US Class Current: 422/82.09
• CPC Class Codes: G01N 15/1434 Optical arrangements
• CPC Class Codes: G01N 2021/4707 Forward scatter; Low angle scatter
• CPC Class Codes: G01N 2201/0612 Laser diodes
• CPC Class Codes: G01N 33/49 Blood chemical methods for determining blood cell populations G01N33/5094; chemical analysis of blood groups or blood types G01N33/80
• CPC Class Codes: G01N 33/493 urine

Abstract

A flow cytometer includes a flow cell for flowing a sample liquid in a flowing direction, to form a sample flow the sample liquid containing particles to be analyzed, a laser diode radiating a laser beam having an elliptic cross section, a beam collimating section for collimating the laser beam radiated from the laser diode, a beam spot forming section for focusing the collimated beam at the sample flow in the flow cell to form a beam spot, and a light receiving section for receiving light generated from the particles at the beam spot to detect optical information of the particles, wherein the laser diode is arranged such that a minor diameter of the elliptic section of the laser beam is parallel to the sample flow.

Claims

1. A flow cytometer, comprising:

a flow cell for flowing, therein, a sample liquid in a flowing direction to form a sample flow, the sample liquid containing particles to be analyzed;

a laser diode radiating a laser beam having an elliptic cross section;

a beam collimating section for collimating the laser beam radiated from the laser diode;

a beam diffusing section for diffusing the collimated beam in a direction perpendicular to the flowing direction;

a beam spot forming section for focusing the diffused beam at the sample flow in the flow cell to form a beam spot, the beam spot being an ellipse having a minor diameter in the flowing direction and a major diameter perpendicular to the flowing direction; and

a light receiving section for receiving light generated from the particles at the beam spot to detect optical information of the particles,

wherein the laser diode is arranged such that a minor diameter of the elliptic cross section of the laser beam is parallel to the flowing direction.

2. A flow cytometer claimed in claim 1, wherein the laser beam radiated from the laser diode has a wavelength of 700 nm or less.

3. A flow cytometer claimed in claim 1, wherein the beam collimating section includes a collimator lens.

4. A flow cytometer claimed in claim 1, wherein the sample liquid is prepared by using a urine specimen.

5. A flow cytometer claimed in claim 1, wherein the particles include bacteria.

6. A flow cytometer claimed in claim 1, wherein the beam diffusing section includes a cylindrical lens.

7. A flow cytometer claimed in claim 6, wherein the cylindrical lens includes a concave cylindrical lens.

8. A flow cytometer claimed in claim 1, wherein the sample flow is sheathed with a sheath flow in the flow cell.

9. A flow cytometer claimed in claim 1, wherein the beam spot forming section includes a condenser lens.

10. A flow cytometer claimed in claim 1, further comprising:

a condenser lens for converging the light generated from the particles to the light receiving section.

11. A flow cytometer claimed in claim 10, further comprising:

a beam stopper, arranged between the flow cell and the condenser lens, for shielding a direct beam passing through the flow cell.

12. A flow cytometer, comprising:

a light source for emitting a collimated light beam;

a photoelectric detector;

a flow cell for flowing, therein, a sample liquid in a flowing direction to form a sample flow, the sample liquid containing particles to be analyzed;

a cylindrical lens system including a first cylindrical lens and a second cylindrical lens, the first cylindrical lens converging the collimated light beam in a direction perpendicular to the flowing direction and the second cylindrical lens diffusing the converged light beam in the direction perpendicular to the flowing direction;

a first condenser lens for converging the diffused light beam at the sample flow in the flow cell to form a beam spot, the beam spot being an ellipse having a minor diameter in the flowing direction and a major diameter perpendicular to the flowing direction;

a second condenser lens for converging light generated from the particles to the photoelectric detector; and

a beam stopper, arranged between the flow cell and the second condenser lens, for shielding a direct beam passing through the flow cell.

13. A flow cytometer claimed in claim 12, wherein the cylindrical lens system adjusts the light beam such that the light beam forms a first beam spot on the sample flow and passes through the flow cell to form a second beam spot on the beam stopper, the first beam spot being shaped as an ellipse having a major diameter perpendicular to the sample flow, the second beam spot being shaped as an ellipse having a minor diameter perpendicular to the sample flow.

14. A flow cytometer claimed in claim 13, wherein the sample flow is sheathed with a sheath flow in the flow cell, the first beam spot having a major diameter substantially equal to a width of the sample and sheath flows and the minor diameter of the second beam spot is minimized.

15. A flow cytometer claimed in claim 12, wherein the beam stopper includes an elongated shielding member extending along the sample flow and arranged at a forming position of the light beam adjusted by the cylindrical lens system.

16. A flow cytometer claimed in claim 12, wherein the first cylindrical lens includes a convex cylindrical lens and the second cylindrical lens includes a concave cylindrical lens.

17. A flow cytometer claimed in claim 12, wherein the light source includes a laser diode radiating a laser beam having an elliptic cross section and a collimating lens for collimating the laser beam from the laser diode, the laser diode being arranged such that the elliptic cross section has a major diameter perpendicular to the sample flow.