Patent ID: 6816257
Filing Date: 2004-11-09
Classification: C12Q,G01N,G02B

Abstract:
A device for detecting a microparticle in a fluid, the microparticle being tagged with a fluorescent substance, the fluorescent substance emitting fluorescent light of predetermined wavelengths when exposed to electromagnetic radiation, the device comprising:a capillary tube having an internal diameter configured to admit the microparticles one at a time; a fluid delivery system coupled to the capillary tube, the fluid delivery system capable of causing the microparticle and the fluid to flow through the capillary tube; a source of electromagnetic radiation for projecting a beam of electromagnetic radiation of predetermined wavelength and size of the capillary tube through said capillary tube whereby the beam size and the interior of the capillary tube define a test volume which exposes the fluorescent substance in the test volume to the electromagnetic radiation to cause emission of fluorescent light by said fluorescent microparticles in said volume; a detection device configured and disposed to detect fluorescent light emitted from the fluorescent substance in the volume when the microparticle is in the capillary volume and provide an output signal; and means disposed between said fluorescent substance in said volume and the detector to pass light at said predetermined wavelengths.