Patent ID: 6177277
Filing Date: 2001-01-23
Classification: G01N

Abstract:
A flow fluorometric method wherein a signal from the fluorescent particles is obtained from a diffraction limited focal volume, comprising1) providing a flow cytometer comprising a focal volume of excitation and a focal volume of detection which are (i) both located within a flow cuvette having a flow channel, and (ii) both smaller than a volume of the flow channel;2) exciting a sample flowing within said flow cuvette so as to cause said sample containing fluorescent particles to emit a fluorescent signal;3) detecting said fluorescent signal; whereina) discrimination between background counts and counts from true fluorescent particles in the sample is based on auto-correlation analysis of single photon counts in the time domain orb) discrimination between the background counts and the counts from true fluorescent particles in the sample is based on cross-correlation analysis of the single photon counts from parallel detectors operating in the same or different spectral signal regions.