Single particle detection device, single particle detection method, and computer program for single particle detection, using optical analysis

A single particle detection device which detects a single particle dispersed and moving at random in a sample solution using an optical system of a confocal microscope or a multiphoton microscope, comprising:na light detection region mover which moves a position of a light detection region of the optical system in the sample solution;a light detector which detects light from the light detection region; anda signal processor which generates time series light intensity data of the light from the light detection region detected with the light detector with moving the position of the light detection region in the sample solution and detects a signal indicating an existence of each single particle individually in the time series light intensity data;wherein the light from the light detection region includes substantially constant background light; and the signal indicating an existence of each single particle is a reduction of the light intensity detected with the light detector, which reduction occurs when the single particle enters into the light detection region,wherein the signal processor makes the time series light intensity data smoothed, and detects in the smoothed time series light intensity data a downwardly convex, bell-shaped pulse form signal whose intensity is lower than a predetermined threshold value measured from an intensity of the background light as the signal indicating the existence of the single particle.

A single particle detection method of detecting a single particle dispersed and moving at random in a sample solution using an optical system of a confocal microscope or a multiphoton microscope, comprising:n(a) moving a position of a light detection region of the optical system in the sample solution;(b) detecting light including substantially constant background light from the light detection region with moving the position of the light detection region in the sample solution, and generating time series light intensity data; and(c) detecting in the time series light intensity data individually a reduction of an light intensity occurring when the single particle has entered into the light detection region as a signal indicating an existence of each single particle,wherein, in the step (c), the time series light intensity data is smoothed, and a downwardly convex, bell-shaped pulse form signal whose intensity is lower than a predetermined threshold value measured from an intensity of the background light in the smoothed time series light intensity data is detected as the signal indicating the existence of the single particle.

A computer readable storage device having a computer program product including programmed instructions for single particle detection of detecting light from a single particle dispersed and moving at random in a sample solution using an optical system of a confocal microscope or a multiphoton microscope, said programmed instructions causing a computer to perform steps of:nmoving a position of a light detection region of the optical system in the sample solution;detecting light including substantially constant background light from the light detection region with moving the position of the light detection region in the sample solution, and generating time series light intensity data; anddetecting in the time series light intensity data individually a reduction of a light intensity occurring when the single particle has entered into the light detection region as a signal indicating an existence of each single particle,wherein, in the procedure of detecting the signal indicating the existence of the single particle individually, the time series light intensity data is smoothed, and a downwardly convex, bell-shaped pulse form signal whose intensity is lower than a predetermined threshold value measured from an intensity of the background light in the smoothed time series light intensity data is detected as the signal indicating the existence of the single particle.