Particle or cell analyzer and method

A particle analyzing apparatus for analyzing a sample comprising

• a capillary tube having a predetermined internal cross-section having one end suspended,
• a pump connected to one end of the capillary tube for drawing sample into the tube through the suspended end of the capillary tube,
• a source of light,
• an optical system for receiving and focusing the light from said source to form and direct a thin rectangular beam through said capillary tube to define an analyzing volume in said capillary tube, said capillary tube selected to have a diameter which causes substantially all particles to be singulated as they pass through said analyzing volume,
• at least one detector for detecting those particles in which fluorescence is excited by said beam, and
• a detector for detecting all particles which pass through said analyzing volume.

A particle analyzing apparatus comprising:

• a capillary tube of predetermined internal cross-section selected such as to singulate particles flowing therethrough,
• a tee, a pump connected to one arm of said tee,
• a capillary conduit extending from another arm of said tee and connected to one end of the capillary tube,
• a discharge conduit and a valve connected to the other arm of said tee, whereby when the valve is closed, the pump can draw fluid from the other end of the capillary through said capillary, and when the valve is opened the pump can discharge fluid sample previously drawn through the capillary,
• a light source for illuminating a predetermined analyzing volume of fluid in said capillary tube,
• at least one detector for detecting fluorescent light emitted by particles flowing through said volume in response to said illumination, and
• a detector for detecting particles which flow through said analyzing volume.

Method of detecting particles in a sample fluid which comprises the steps of:

• providing a capillary tube of predetermined internal cross-section with a suspended end,
• drawing the sample fluid through the suspended end of said capillary tube and through the capillary tube to cause substantial singulation of the particles,
• focusing a beam of light onto the capillary tube to illuminate particles in an analyzing volume bounded by the walls in one direction and the beam size in the other direction, and
• detecting fluorescent light emitted by tagged particles in response to the illumination of said volume, and providing an output signal.

A particle analyzing apparatus for analyzing a sample comprising:

• an elongated capillary tube having a predetermined internal cross-section,
• a pump connected to one end of the capillary tube for drawing sample into the other end of the capillary tube and through the capillary tube to cause particles to flow along said capillary tube,
• a light source for illuminating a predetermined analyzing volume of sample in the capillary tube,
• means for gathering a fluorescent light emitted by said particles excited by illumination impinging on the particles, and
• at least one detector for receiving said gathered fluorescent light.