Abstract: An apparatus and method for determining the density and fluid-type of a fluid flowing in a capillary tube, the velocity and viscosity of a blood sample flowing in a capillary tube, the erythrocyte sedimentation rate (ESR) of a blood sample after flow has been brought to an abrupt stop in a capillary tube, and/or the zeta sedimentation rate (ZSR) of a blood sample after flow has been brought to an abrupt stop in a capillary tube. These measurements are accomplished by directing a waveform pulse, such as an ultrasound pulse, at a pre-determined frequency transversely across the capillary tube and sample fluid, and by determining the flight of time of the pulse through the capillary tube and sample fluid and/or the Doppler shift of the echo signals reflecting off cells moving forwardly or transversely within a flowing, or stationary, blood sample.

Abstract: A stellar icon for representing multivariate data includes finger members corresponding to constituents of a sample with a length corresponding to an expression of an attribute of the constituent. The finger members are positioned on the base member so that the finger members corresponding to a constituent with an expression of attribute within a certain range are on the upper portion of the base member, and the finger members corresponding to a constituent with an expression of an attribute that is not in the range are positioned on the lower portion of the base member. A method and system for forming the stellar icon include forming a transformation table including data regarding the range and constituents and attributes to be represented. The transformation table is used to determine the relative position of each finger member on the base member and to determine the length of the finger member so that the length corresponds to the expression of the attribute.

Abstract: A composition for enhancing differential staining of RNA, DNA and granules in a sample comprising cells contains a first fluorescent dye that can bind specific binding sites and non-specific binding sites in the sample. This first dye emits fluorescence at a first wavelength. The composition contains at least an additional component, which is a second non-intercalating dye in the composition that competes with said first dye for binding to the nonspecific binding sites, or a permeabilizing agent to enhance permabilization of the dyes into the cells, or both. The molar ratio of the second dye and the first dye is at least about 20:1.

Abstract: Methods, systems and apparatus are provided for sorting particles in a stream of a sample in a flow cytometer by producing from a stable sort having desirable sort characteristics multiple images of a portion of the stream; generating from the multiple images an averaged numerical reference standard representative of the stable sort; continuously collecting during the sorting multiple running images of the portion of the stream; generating from the multiple running images at least one numerical sample average representative of the sample sort of each collection of the multiple running images; and comparing each numerical sample average to the numerical reference standard and determining whether a sample average exhibits a deviation from the reference standard that requires an adjustment of the sort. The sort may then be adjusted to eliminate or reduce the deviation and maintain the stable sort of the reference histogram. A novel imaging apparatus may be employed in a flow cytometer performing this method.

Abstract: Apparatus for detecting light scattered by a small particle (e.g., a blood cell) irradiated by a light beam comprises one or more photodetectors and a plurality of optical fibers that serve to optically couple the scattered light and the photodetector(s). To enhance the efficiency of such optical coupling, a portion of each of the optical fibers in the vicinity of its light-collecting end is supported so that its optical axis extends towards the light-scattering source. By this arrangement, scattered light enters each fiber from a direction substantially parallel to the fiber axis. Preferably, the light-collecting ends of the optical fibers are supported on a concave surface and so that the respective optical axes of the fibers converge at a point representing the apparent position of the light-scattering source, taking into account the refractive effects of an optical flow cell through which scattering is detected.

Abstract: A back-scatter detector for detecting light scattered backwardly (i.e., reflected) by an irradiated particle such as a blood cell comprises a plurality of optical fibers. A fiber optic holder having a centrally located opening for passing a light beam used to irradiate particles at a particle-interrogation zone serves to position the light-collecting ends at a desired position to collect back-scattered light. Preferably, the light-collecting ends of the optical fibers are positioned in a circular pattern centered about the irradiating light beam, and the respective axes of the supported portions of the optical fibers extend either parallel to the beam axis, or, more preferably, so that they converge at or near the location of the scattering source, i.e., the irradiated particle or cell. The latter configuration assures that the back-scatter light enters the fiber end substantially parallel to the fiber axis, thereby reducing optical transmission loses in the fiber.

Abstract: A kit for assessing the level of pentraxin-binding moieties on particles in a biological sample containing a ligand comprising a pentraxin is useful in a method of assessing pentraxin-binding of particles for use in diagnosis of disease or abnormality. The method includes the steps of (a) exposing a biological test sample containing particles that comprise a pentraxin-binding receptor from a test subject to a ligand comprising a pentraxin in the presence of calcium; (b) determining quantitatively the level of binding between particles and ligand in said test sample; and (c) comparing the level of binding in said test sample to the level of binding in a control biological sample containing said particles from a healthy subject of the same species as the subject supplying the test sample. A change in the level of binding in said test sample from that of the control sample is indicative of disease or abnormality.

Abstract: A shear valve assembly comprises a pair of valve pads having opposing planar surfaces supported for relative sliding engagement. Each valve pad defines a plurality of liquid pathways by which a liquid can be passed from one pad to the other. The planar surface of one of the valve pads has an open channel formed therein, such channel having dimensions to accommodate a prescribed volume of liquid. Liquid is introduced into such channel via a first pair of pathways formed in the other valve pad, and liquid is dispensed from the open channel by a second pair of pathways that are brought into alignment with the channel during sliding movement between the valve pads. The valve assembly is particularly useful in blood-analyzing instruments for isolating and dispensing relatively minute volumes (of the order of microliters) of whole blood for analysis.

Abstract: An apparatus and method in which a still image, or still images, are obtained of a plurality of particles suspended in a fluid medium. Each still image is transferred to an image analyzing unit that measures a set of dimensional characteristics per particle for particles appearing in the image and determine an occurrence characteristic for particles having a matching set of dimensional characteristics. Preferably, a three dimensional representation of the characteristics is displayed in real time. More preferably, the displayed three-dimensional representation is continuously updated and further entries are accumulated on the display as image analysis is performed. The display provides information to a viewer enabling the viewer to determine a shape distribution of the particles within the suspension even when multiple particle shapes are present.

Abstract: Blood cells of interest are readily distinguishable from other blood cells and look-a-like particles found in a blood sample by their back-scatter signature. A preferred method for differentiating platelets in a blood sample is to irradiate the cells and particles, one at a time, with a beam of radiation, and to detect back-scattered (reflected) radiation using a plurality of optical fibers to transmit the back-scattered radiation to a high-gain photodetector, e.g. a photomultiplier tube. Preferably, the back-scatter signal so obtained is combined with a second signal representing, for example, either the level of forward-scatter within a prescribed, relatively narrow angular range, or the level of side-scattered radiation, or the level of attenuation of the cell-irradiating beam caused by the presence of the irradiated cell or particle in the beam, or the electrical impedance of the irradiated cell or particle, to differentiate the cells of interest.

Abstract: A particle sizing method and apparatus of the PIDS type uses randomly polarized radiation to irradiate a particle sample. Portions of the resulting side scattering pattern are decomposed to simultaneously produce, for each decomposed portion, first and second linearly polarized beams of radiation in which the respective planes of polarization of the two beams are mutually perpendicular. Each of the polarized beams is focused onto a photodetector, and the respective photodetector outputs are differentiated to provide PIDS signals that are useful in calculating a particle size distribution for the sample.

Abstract: Apparatus for detecting light scattered by a small particle (e.g., a blood cell) irradiated by a light beam comprises one or more photodetectors and a plurality of optical fibers that serve to optically couple the scattered light and the photodetector(s). To enhance the efficiency of such optical coupling, a portion of each of the optical fibers in the vicinity of its light-collecting end is supported so that its optical axis extends towards the light-scattering source. By this arrangement, scattered light enters each fiber from a direction substantially parallel to the fiber axis. Preferably, the light-collecting ends of the optical fibers are supported on a concave surface and so that the respective optical axes of the fibers converge at a point representing the apparent position of the light-scattering source, taking into account the refractive effects of an optical flow cell through which scattering is detected.

Abstract: Blood cells of interest are readily distinguishable from other blood cells and look-a-like particles found in a blood sample by their back-scatter signature. A preferred method for differentiating platelets in a blood sample is to irradiate the cells and particles, one at a time, with a beam of radiation, and to detect back-scattered (reflected) radiation using a plurality of optical fibers to transmit the back-scattered radiation to a high-gain photodetector, e.g. a photomultiplier tube. Preferably, the back-scatter signal so obtained is combined with a second signal representing, for example, either the level of forward-scatter within a prescribed, relatively narrow angular range, or the level of side-scattered radiation, or the level of attenuation of the cell-irradiating beam caused by the presence of the irradiated cell or particle in the beam, or the electrical impedance of the irradiated cell or particle, to differentiate the cells of interest.

Abstract: Apparatus for detecting light scattered by a small particle (e.g., a blood cell) irradiated by a light beam comprises one or more photodetectors and a plurality of optical fibers that serve to optically couple the scattered light and the photodetector(s). To enhance the efficiency of such optical coupling, a portion of each of the optical fibers in the vicinity of its light-collecting end is supported so that its optical axis extends towards the light-scattering source. By this arrangement, scattered light enters each fiber from a direction substantially parallel to the fiber axis. Preferably, the light-collecting ends of the optical fibers are supported on a concave surface and so that the respective optical axes of the fibers converge at a point representing the apparent position of the light-scattering source, taking into account the refractive effects of an optical flow cell through which scattering is detected.

Abstract: A composition for enhancing differential staining of RNA, DNA and granules in a sample comprising cells contains a first fluorescent dye that can bind specific binding sites and non-specific binding sites in the sample. This first dye emits fluorescence at a first wavelength. The composition contains at least an additional component, which is a second non-intercalating dye in the composition that competes with said first dye for binding to the nonspecific binding sites, or a permeabilizing agent to enhance permabilization of the dyes into the cells, or both. The molar ratio of the second dye and the first dye is at least about 20:1.

Abstract: A signal processing operator successfully expands the dynamic range of a histogram of digital data, such as that representative of biological cell populations, including human blood cells subjected to flow cytometry processing, without introducing binning artifacts into the transformed data. The inventive data mapping scheme effectively preserves statistical probability distribution characteristics of the original data, that would otherwise be removed or lost in the course of expanding the dynamic range of a quantized histogram data set through the use of a conventional log transformation. Filtering is unnecessary, as the binning effect is countered early in the process, to preserve statistical properties of the cell populations under study.

Abstract: A particle sizing method and apparatus of the PIDS type uses randomly polarized radiation to irradiate a particle sample. Portions of the resulting side scattering pattern are decomposed to simultaneously produce, for each decomposed portion, first and second linearly polarized beams of radiation in which the respective planes of polarization of the two beams are mutually perpendicular. Each of the polarized beams is focused onto a photodetector, and the respective photodetector outputs are differentiated to provide PIDS signals that are useful in calculating a particle size distribution for the sample.

Abstract: A method for utilizing a filtration device for removing interferants from a sample containing cells in an automated apparatus is disclosed. The filtration device includes a microporous hollow fiber membrane having a plurality of pores sized to retain cells while allowing smaller diameter interferants to pass through the membrane. The apparatus also includes a means for of moving the sample from a sample container to and from the filtration device. The disclosed method utilizes a vacuum source to aspirate the sample into a lumen of the hollow fiber membrane so that the sample is retained in the lumen space until expelled into an analysis container or transported to an analyzer.

Abstract: A method for utilizing a filtration device for removing interferants from a test sample containing a mixture of a composition of interest and interferants in an automated apparatus is disclosed. The filtration device includes a microporous hollow fiber membrane having a plurality of pores sized to retain the composition of interest while allowing smaller diameter interferants to pass through the membrane.

Abstract: Blood cells of interest are readily distinguishable from other blood cells and look-a-like particles found in a blood sample by their back-scatter signature. A preferred method for differentiating platelets in a blood sample is to irradiate the cells and particles, one at a time, with a beam of radiation, and to detect back-scattered (reflected) radiation using a plurality of optical fibers to transmit the back-scattered radiation to a high-gain photodetector, e.g. a photomultiplier tube. Preferably, the back-scatter signal so obtained is combined with a second signal representing, for example, either the level of forward-scatter within a prescribed, relatively narrow angular range, or the level of side-scattered radiation, or the level of attenuation of the cell-irradiating beam caused by the presence of the irradiated cell or particle in the beam, or the electrical impedance of the irradiated cell or particle, to differentiate the cells of interest.