METHOD AND APPARATUS FOR PHOTOANALYSIS

• US 3,788,744 A
• Filed: 12/06/1971
• Issued: 01/29/1974
• Est. Priority Date: 01/14/1970
• Status: Expired due to Term

• Current Assignee: Isaac Klinger, Louis A. Kamentsky, Mitchell Friedman
• Original Assignee: Isaac Klinger, Louis A. Kamentsky, Mitchell Friedman
• Inventors: Kamentsky, Louis A., Klinger, Isaac, Friedman, Mitchell
• Primary Examiner(s): Schonberg, David
• Assistant Examiner(s): Clark, Conrad
• Application Number:
  US05/205,434
• Time in Patent Office: 785 Days
• Field of Search: 356/39,102,103,173,186,201,104 250/71R
• US Class Current: 356/39
• CPC Class Codes: G01N 15/1434 Optical arrangements
• CPC Class Codes: G01N 2021/4707 Forward scatter; Low angle scatter
• CPC Class Codes: G01N 2021/4709 Backscatter
• CPC Class Codes: G01N 2021/4711 Multiangle measurement

Abstract

A narrow beam of monochromatic light is directed through an optical chamber to intersect a thin stream of small particles to be optically analyzed, causing the particles to emit fluorescent radiation in the presence of a significant particle characteristic to be detected. A spectral filtering element is positioned to intercept the fluorescent particle radiation and to pass only a selected wave length to a photoresponsive pick-up element for detection thereby.

Claims

1. An apparatus for rapid optical measurement of the characteristics of small particles such as blood cells while the particles are suspended in a liquid, comprising a source of light, a cylindrical tube member defining an optical chamber, said tube member being comprised of a material which transmits light from said source, means for directing said light into one side of said tube member in a beam substantially converging at the center of said optical chamber when viewed in a direction perpendicular to the axis of said tube member defining said chamber, means for moving the particle suspending liquid through said tube member in a thin stream to cause the particles therein to pass in sequence through said light beam one by one, at least one photoresponsive pick-up element for detecting light scattered by said particles positioned on the side of said tube member opposite to said light source and displaced away from the direct path of said light beam through said tube member in a direction parallel to the axis of said tube member, said light source comprising a source of mono-chromatic light, a second photoresponsive pick-up element in addition to said scattered light detecting photoresponsive pick-up element, a spectral filtering element positioned to filter the light received by said second photoresponsive pick-up element, said spectral filtering element being selected to exclude light at the wave length of said light source and to pass light to the associated photoresponsive pick-up element at a wave length for which the particles under investigation emit fluorescent radiation in the presence of a significant particle characteristic to be detected, and optical means substantially surrounding the circumference of said cylindrical tube member optical chamber for gathering fluorescent radiation directed radially outwardly from the particles and for directing the fluorescent radiation through said spectral filtering element to said second photoresponsive pick-up element.

2. Apparatus as claimed in claim 1 wherein there is provided a third photoresponsive pick-up element positioned outside of said chamber and a second spectral filtering element positioned to filter the light received by said third photoresponsive pick-up element, said second spectral filtering element being selected to exclude light at the wave length of said light source and at the wave length passed by said first-mentioned spectral filtering element and operable to pass light to the associated photoresponsive pick-up element at a wave length for which the particles under investigation emit fluorescent radiation in the presence of a second significant particle characteristic to be detected.

3. Apparatus as claimed in claim 2 wherein said optical means for gathering and directing fluorescent radiation includes a dichroic mirror operable to reflect fluorescent radiation to one of said spectral filtering elements and the photoresponsive pick-up element associated therewith, and operable to transmit fluorescent radiation to the other one of said spectral filtering elements and the photoresponsive picK-up element associated therewith.

4. An apparatus for rapid optical measurement of the characteristics of small particles such as blood cells while the particles are suspended in a liquid, comprising a source of substantially monochromatic light, a cylindrical tube member defining an optical chamber, said tube member being comprised of a material which transmits light from said source, means for directing said light into one side of said tube member in a beam substantially converging at the center of said optical chamber when viewed in a direction perpendicular to the axis of said tube member defining said chamber, means for moving the particle suspending liquid through said tube member in a thin stream to cause the particles therein to pass in sequence through said light beam one by one, at least one photoresponsive pick-up element positioned outside of said tube member and displaced away from the direct path of said light beam through said tube member, said pick-up element being operable to respond to fluorescent radiation emitted by said particles in the presence of said light beam, a spectral filtering element positioned to filter the light received by said pick-up element, said spectral filtering element being selected to exclude light at the wave length of said light source and to pass light to said pick-up element at a wave length for which the particles under investigation emit fluorescent radiation in the presence of a significant particle characteristic to be detected, and optical means substantially surrounding the circumference of said optical chamber and operable to gather fluorescent radiation directed radially outwardly through the walls of said optical chamber from the particles and for directing the fluorescent radiation through said spectral filtering element to said photoresponsive pick-up element.

5. Apparatus as claimed in claim 4 wherein there is provided a second photoresponsive pick-up element positioned in alignment with the light beam on the side of said housing opposite to said light source to receive the unscattered illumination from the light beam.

6. Apparatus as claimed in claim 4 wherein a second photoresponsive pick-up element is positioned outside of said tube member to receive fluorescent radiation from the particles gathered by said optical means for gathering fluorescent radiation, a second spectral filtering element positioned to filter the light received by said second pick-up element, said second spectral filtering element being selected to exclude light at the wave length of said light source and to pass light to said second pick-up element at a wave length for which the particles under investigation emit fluorescent radiation in the presence of a significant particle characteristic to be detected which is different from the characteristic detected by fluorescent radiation received by said previously mentioned pick-up element.

7. Apparatus as claimed in claim 6 wherein a dichroic mirror is provided and positioned between said optical means for gathering fluorescent radiation from the particles and said spectral filtering elements, said dichroic mirror being operable to reflect fluorescent radiation to one of said spectral filtering elements and the photoresponsive pick-up element associated therewith, and said dichroic mirror being operable to transmit fluorescent radiation to the other one of said spectral filtering elements and the photoresponsive pick-up element associated therewith.

8. Apparatus as claimed in claim 4 wherein said means for moving the particle suspending liquid through said tube member in a thin stream includes means for providing a sheath of liquid flowing in an annular configuration through said tube member and surrounding said thin stream to thereby confine the thin stream of particle suspending liquid to a dimension smaller than the interior diameter of said tube member.

9. Apparatus as claImed in claim 4 wherein said light source is a laser.

10. Apparatus as claimed in claim 9 wherein said laser is an argon ion laser.

11. An apparatus for rapid optical measurement of the characteristics of small particles such as blood cells while the particles are suspended in a liquid comprising a cylindrical tubular housing defining an optical chamber, a source of substantially monochromatic light, said optical chamber being comprised of a material which transmits light from said source, means for moving the particle suspending liquid through said optical chamber in a thin narrow stream to thereby convey the particles in sequence through the light beam one by one, means for directing light from said light source into one side of said optical chamber to intersect with the thin stream carrying the particles therein, said means for directing said light being operable in cooperation with said side of said optical chamber to converge said light beam into a substantially elliptical shape in a plane transverse to the light beam and at the point of intersection with the position of the thin stream of particles, the major axis of the elliptical shape of said beam being substantially perpendicular to the direction of the stream of particles and the dimension of said beam at said major axis being substantially greater than the transverse dimension of said particle stream, at least one photoresponsive pick-up element positioned outside of said optical chamber, said pick-up element being operable to respond to fluorescent radiation emitted by said particles in the presence of said light beam, a spectral filtering element positioned to filter the light received by said pick-up element, said spectral filtering element being selected to exclude light at the wave length of said light source and to pass light to said pick-up element at a wave length for which the particles under investigation emit fluorescent radiation in the presence of a significant particle characteristic to be detected, and optical means substantially surrounding the circumference of said optical chamber and operable to gather fluorescent radiation directed radially outwardly through the walls of said optical chamber from the particles and for directing the fluorescent radiation through said spectral filtering element to said photoresponsive pick-up element.

12. Apparatus as claimed in claim 11 wherein said means for directing light from said light source comprises a substantially cylindrical lens device.

13. A method for rapidly detecting biological cells having different properties including the steps of exposing a solution containing the cells to be analyzed to a dye which is taken up differently by cells having different characteristics, moving the particle suspending liquid solution in a thin stream to convey the particles one by one through a cylindrical tubular optical chamber while directing light from a substantially monochromatic light source into one side of the chamber to intersect with the thin stream of particles in a narrow beam, the narrow beam converging at the stream of particles, gathering fluorescence radiation signals emitted by the stained cells when excited by the light beam and radiated radially outwardly from the circumference of the housing, detecting said radiation signals by means of at least one photoresponsive pick-up element positioned outside of the housing, and filtering the fluorescence radiation signals directed to the pick-up element to exclude light at the wave length of said light source and to pass light to the pick-up element at a wave length for which the particles under investigation emit fluorescent radiation in the presence of a significant particle characteristic to be detected.