Abstract: A particle sizing method which allows for counting and sizing of particles within a colloidal suspension flowing through a single-particle optical sizing sensor SPOS apparatus using pulse height detection and utilizing non-parallel and non-uniform illumination within the sensing region of the flow cell. The method involves utilizing a deconvolution process which requires the SPOS apparatus to be characterized during a calibration phase. Once the SPOS apparatus has been characterized, the process of deconvolution after a data collection run, recursively eliminates the expected statistical contribution to the pulse height distribution PHD histogram in all the lower channels from the highest channel height detected, and repeating this for all remaining channels in the PHD, removing the contributions from largest to smallest sizes.

Abstract: A particle sizing method which allows for counting and sizing of particles within a colloidal suspension flowing through a single-particle optical sizing sensor SPOS apparatus using pulse height detection and utilizing non-parallel and non-uniform illumination within the sensing region of the flow cell. The method involves utilizing a deconvolution process which requires the SPOS apparatus to be characterized during a calibration phase. Once the SPOS apparatus has been characterized, the process of deconvolution after a data collection run, recursively eliminates the expected statistical contribution to the pulse height distribution PHD histogram in all the lower channels from the highest channel height detected, and repeating this for all remaining channels in the PHD, removing the contributions from largest to smallest sizes.

Abstract: A particle sizing method which allows for counting and sizing of particles within a colloidal suspension flowing through a single-particle optical sizing sensor SPOS apparatus using pulse height detection and utilizing non-parallel and non-uniform illumination within the sensing region of the flow cell. The method involves utilizing a deconvolution process which requires the SPOS apparatus to be characterized during a calibration phase. Once the SPOS apparatus has been characterized, the process of deconvolution after a data collection run, recursively eliminates the expected statistical contribution to the pulse height distribution PHD histogram in all the lower channels from the highest channel height detected, and repeating this for all remaining channels in the PHD, removing the contributions from largest to smallest sizes.

Abstract: A particle sizing method which allows for counting and sizing of particles within a colloidal suspension flowing through a single-particle optical sizing sensor SPOS apparatus using pulse height detection and utilizing non-parallel and non-uniform illumination within the sensing region of the flow cell. The method involves utilizing a deconvolution process which requires the SPOS apparatus to be characterized during a calibration phase. Once the SPOS apparatus has been characterized, the process of deconvolution after a data collection run, recursively eliminates the expected statistical contribution to the pulse height distribution PHD histogram in all the lower channels from the highest channel height detected, and repeating this for all remaining channels in the PHD, removing the contributions from largest to smallest sizes.

Abstract: A new device capable of measuring the number of particles present in a colloidal suspension is disclosed, which includes a forward scatter detector, an extinction detector, a laser beam, a cylindrical lens with which to create a plane of light through which particles can pass, and the various pumps and tubing needed to pass the colloidal suspension through the plane of light. The device is particularly designed for measuring particles which have different refractive indices, and which are in the size range of between about 0.7 to 2 microns. The device can determine the presence or absence of biological particles of interest in a given sample, by incubating a sample with a given ratio of active particles and marker particles, and determining whether the ratio of active particles and marker particles has changed. Additional binding and/or non-binding particles can also be present, and kits including the particles are also disclosed.

Abstract: A new device capable of measuring the number of particles present in a colloidal suspension is disclosed, which includes a forward scatter detector, an extinction detector, a laser beam, a cylindrical lens with which to create a plane of light through which particles can pass, and the various pumps and tubing needed to pass the colloidal suspension through the plane of light. The device is particularly designed for measuring particles which have different refractive indices, and which are in the size range of between about 0.7 to 2 microns. The device can determine the presence or absence of biological particles of interest in a given sample, by incubating a sample with a given ratio of active particles and marker particles, and determining whether the ratio of active particles and marker particles has changed. Additional binding and/or non-binding particles can also be present, and kits including the particles are also disclosed.

Abstract: A single-particle optical sensor, which has high sensitivity and responds to relatively concentrated suspensions, uses a relatively narrow light beam to illuminate an optical sensing zone nonuniformly. The zone is smaller than the flow channel so that the sensor responds to only a fraction of the total number of particles flowing through the channel, detecting a statistically significant number of particles of any relevant diameter. Because different particle trajectories flow through different parts of the zone illuminated at different intensities, it is necessary to deconvolute the result. Two methods of deconvolution are used: modified matrix inversion or successive subtraction. Both methods use a few basis vectors measured empirically or computed from a theoretical model, and the remaining basis vectors are derived from these few. The sensor is compensated for turbidity. Several embodiments are disclosed employing light-extinction or light-scattering detection, or both.

Abstract: A single-particle optical sensor, which has high sensitivity and responds to relatively concentrated suspensions, uses a relatively narrow light beam to illuminate an optical sensing zone nonuniformly. The zone is smaller than the flow channel so that the sensor responds to only a fraction of the total number of particles flowing through the channel, detecting a statistically significant number of particles of any relevant diameter. Because different particle trajectories flow through different parts of the zone illuminated at different intensities, it is necessary to deconvolute the result. Two methods of deconvolution are used: modified matrix inversion or successive subtraction. Both methods use a few basis vectors measured empirically or computed from a theoretical model, and the remaining basis vectors are derived from these few. The sensor is compensated for turbidity. Several embodiments are disclosed employing light-extinction or light-scattering detection, or both.

Abstract: A single-particle optical sensor, which has high sensitivity and responds to relatively concentrated suspensions, uses a relatively narrow light beam to illuminate an optical sensing zone nonuniformly. The zone is smaller than the flow channel so that the sensor responds to only a fraction of the total number of particles flowing through the channel, detecting a statistically significant number of particles of any relevant diameter. Because different particle trajectories flow through different parts of the zone illuminated at different intensities, it is necessary to deconvolute the result. Two methods of deconvolution are used: modified matrix inversion or successive subtraction. Both methods use a few basis vectors measured empirically or computed from a theoretical model, and the remaining basis vectors are derived from these few. The sensor is compensated for turbidity. Several embodiments are disclosed employing light-extinction or light-scattering detection, or both.

Abstract: A single-particle optical sensor, which has high sensitivity and responds to relatively concentrated suspensions, uses a relatively narrow light beam to illuminate an optical sensing zone nonuniformly. The zone is smaller than the flow channel so that the sensor responds to only a fraction of the total number of particles flowing through the channel, detecting a statistically significant number of particles of any relevant diameter. Because different particle trajectories flow through different parts of the zone illuminated at different intensities, it is necessary to deconvolute the result. Two methods of deconvolution are used: modified matrix inversion or successive subtraction. Both methods use a few basis vectors measured empirically or computed from a theoretical model, and the remaining basis vectors are derived from these few. The sensor is compensated for turbidity. Several embodiments are disclosed employing light-extinction or light-scattering detection, or both.

Abstract: A single-particle optical sensor, which has high sensitivity and responds to relatively concentrated suspensions, uses a relatively narrow light beam to illuminate an optical sensing zone nonuniformly. The zone is smaller than the flow channel so that the sensor responds to only a fraction of the total number of particles flowing through the channel, detecting a statistically significant number of particles of any relevant diameter. Because different particle trajectories flow through different parts of the zone illuminated at different intensities, it is necessary to deconvolute the result. Two methods of deconvolution are used: modified matrix inversion or successive subtraction. Both methods use a few basis vectors measured empirically or computed from a theoretical model, and the remaining basis vectors are derived from these few. The sensor is compensated for turbidity. Several embodiments are disclosed employing light-extinction or light-scattering detection, or both.

Abstract: A single-particle optical sensor, which has high sensitivity and responds to relatively concentrated suspensions, uses a relatively narrow light beam to illuminate an optical sensing zone nonuniformly. The zone is smaller than the flow channel so that the sensor responds to only a fraction of the total number of particles flowing through the channel, detecting a statistically significant number of particles of any relevant diameter. Because different particle trajectories flow through different parts of the zone illuminated at different intensities, it is necessary to deconvolute the result. Two methods of deconvolution are used: modified matrix inversion or successive subtraction. Both methods use a few basis vectors measured empirically or computed from a theoretical model, and the remaining basis vectors are derived from these few. The sensor is compensated for turbidity. Several embodiments are disclosed employing light-extinction or light-scattering detection, or both.