Abstract: Stabilized reference control and calibrator compositions for determining multiple platelet parameters in stand alone platelet controls and whole blood reference controls are prepared from platelets stabilized with a fixative-stabilizing composition containing glutaraldehyde and a non-ionic surfactant which is a mixture of ethoxylates of certain isomeric linear alcohols.

Abstract: A sample feeding arrangement which receives sealed sample tubes, moves them one at at time to a seal piercing and sample aspiration station, and then discharges the used tubes. This sample feeding arrangement is mounted inside a sample analyzer of the type which previously had operated semiautomatically. Receipt of a sample tube at the infeed station of this feeding arrangement initiates the repositioning of the tube to an aspiration station, which thereat enables all other handling steps of the tube, sample aspiration, and the full system cycle of the analyzer.

Abstract: By subjecting cells, such as red blood cells, to a hypotonic solution or a solution having a lytic agent, the cells will rapidly attain a change in volume and electrical resistance parameters, which change is measured as a function of time, for example, by a Coulter Counter.RTM. particle measuring instrument. The relationship between the change in the cell resistance or cell volume and the time of immersion in the volume changing solution provides a discriminator between a normality, different diseases, and certain inherited differences.

Abstract: Disclosed is a particle analyzing apparatus including a first vessel of particulate electrolyte suspension, and an electrolyte-containing first chamber, and an electrolyte-containing second chamber, a sensing aperture formed in a wall between the vessel and the first chamber, a cleaning orifice formed in a wall between the first chamber and the second chamber, an electrical current passing through the sensing aperture to generate detectable signals with the passage of the particles through the sensing aperture, and a fluid recirculating system providing a fluid path from the second chamber through a filter for removing the particles to the first chamber, which is powered by waste kinetic energy of the suspension exiting from the sensing aperture.

Abstract: A process for preparing whole blood reference controls having long term stability up to six months for devices using electronic means for whole blood determinations including platelet count and mean cell volume and red blood distribution width. The preconditioning diluent for the red blood cells consists essentially of an aqueous solution of lactose, sodium azide, and a non-ionic surfactant and is pH buffered and osmolality adjusted. The media of the whole blood control includes lactose, fungicides and antibiotics, and supplementary agents including purine nucleosides. It also includes additional components which alter red blood cell membranes including bile salts and cholic acid derivatives, phenothiazine compounds and the salts thereof having antihistamine properties, and 4-aminobenzoic acid ester derivatives and their salts having local anesthetic properties.

Abstract: Disclosed is an optical flow system wherein individual particles, which are sequentially suspended in a fluid flow, are irradiated at a detection zone with an excitation source to generate radiation signals, which in turn are dispersed by a concave reflection grating for subsequent detection and measurement. The radiation signals which are not dispersed from the grating but are reflected from the grating, are further reflected by a conjugate mirror to form a projected image of the detection zone suitable for viewing with a screen or eyepiece.

Abstract: A centrifugal feeder includes a cylindrical feeder disc having an upwardly inclined uniform surface which is designed to expel particles placed thereon in a predetermined fashion by centrifugal force. The upwardly inclined surface of the disc may be designed to have a first predetermined expulsion rate which is the initial speed at which the disc must be rotated to expel any of the particles from the surface thereof. The disc also may be designed to have a final expulsion rate at which all particles placed on the surface thereof are expelled. The disc is rotated at a controlled rate of speed and at a controlled rate of change of speed to expel the particles in the manner desired in a linear or non linear fashion. The feed or expulsion rate of the particles is determined by the design of the disc and the rotation speed of the disc and essentially is independent of the size and density of the particles and the viscosity of the surrounding fluid in which the disc is rotated.

Abstract: Disclosed is a substrate holder and method of holding a substrate for a spinner apparatus wherein the holder has a first pair of diagonally positioned locking members under which the substrate is locked during acceleration of the rotating holder and a second pair of diagonally positioned locking members under which the substrate is locked during deceleration of the holder.

Abstract: Disclosed is an electro-optical transducer for simultaneously making optical measurements and electrical volume measurements on particles suspended in a flow stream passing through an orifice positioned inside an optically clear spherical element.

Abstract: An isotonic multipurpose blood diluent, and a method for use of this diluent with a weak lysing reagent system which is especially suitable for routine enumeration of traditional hemogram values, and also the determination of lymphoid-myeloid populations of leukocytes, particularly in automatic particle counting systems.This blood diluent is capable of affording accurate, reproducible test results. It is an osmotically balanced aqueous solution of preselected pH containing Procaine hydrochloride for maintaining erythrocyte morphology during operation, N-(2-acetamido)iminodiacetic acid (ADA) as a blood cell stabilizing agent, and bacteriostatic agents including sodium 1-hydroxypyridine-2-thione, dimethylolurea and chlorhexidene diacetate which, together with the ADA, allow preferential determination of myeloid-lymphoid leukocytes, and other hematological values.

Abstract: In an apparatus in which particles are passed through an optical sensing zone to measure their radiant energy distribution such as, for example, light scattering characteristics for the purpose of identifying the particles, means and a method are provided for deviating the collected light in accordance with predetermined different paths to a plurality of different photodetecting devices. The deviation is effected independently of collection by optical radiant energy transmitting or reflecting means. The different photodetecting devices enable the measurement of energy directed along the particular path which is identified with that device. The paths are established by the deviating means rather than permitted to evolve by the scattering phenomena themselves whereby the photodetecting devices can be located in convenient arrangements and may be conventional in construction.

Abstract: A fluid transfer mechanism for rapidly and accurately picking up or aspirating a fluid quantity or aliquot in one position, moving it to a second position and dispensing the aspirated aliquot. The mechanism includes an arm mounted on a high helix shaft on one end and driven up and down the shaft by a first motor and rotated around the shaft by a second motor. The arm includes at a second end a fluid transfer probe which is moved into and out of the fluids to aspirate and dispense the fluids in precise angular locations. The arm may be accelerated and deaccelerated as it is rotated to avoid vibrations and spilling of the fluid from the probe. The probe may include a level sensing structure for sensing when the probe has contacted a fluid surface. The probe also may be coupled to an oscillator to oscillate the probe in a vessel into which the fluid has been dispensed to mix the fluids therein.

Abstract: A particle analyzing apparatus comprising a reflector chamber containing an electrolyte and having a concave reflector surface with a first focus and a second focus; entraining structure, having an introduction tube for providing and moving a stream of particles suspended in an electrolyte solution through the first focus; a source of radiant energy for illuminating the particles as they pass through the first focus to produce a source of detectable radiation signals, which reflect off the concave reflector surface to be subsequently collected and analyzed; an exit tube coaxially aligned with the introduction tube; a sensing orifice mounted in the tip of the introduction tube or the exit tube; and a pair of energized electrodes disposed in the electrolyte solution on either side of the orifice, whereby the orifice creates a constricted electrical path in which the stream of particles generate electrical impedance signals as they move therethrough.

Abstract: An improved illuminating system for redistributing incident radiation, having a non-uniform intensity distribution, to resultant radiation, having a narrower desired intensity distribution in a predetermined region of an output plane, the illuminating system comprising a redirecting surface of a lens or reflector, for relocating at least a portion of the incident light. In one application, particles are illuminated in the output plane.

Abstract: A level sensor of a fluid transfer mechanism for determining when the bottom tip of a fluid aspirating probe touches or contacts the top surface of a sample fluid. The level sensor senses the contact capacitively by grounding one plate of a capacitor through the sample fluid and fluid aspirating probe. One capacitor plate is formed of an electrode biased against the bottom of a rotatable supply tray and positioned under a sample containing cavity in the tray. The other capacitor plate is formed by the bottom surface of the sample fluid in the supply cavity, and the dielectric of the capacitor is formed of the supply tray material. An AC signal is applied to the electrode and the probe is grounded. The change in voltage occurring in the AC signal at the electrode when the probe touches the top surface of the sample fluid it is sensed to provide the touch signal.

Abstract: A vertically and horizontally movable arm structure for fluid transfer is provided with a tubular member for linear oscillation of a holder for a fluid probe; the tubular member can additionally form a conduit for lead wire connected to the fluid probe. Sensors for the vertical position of the arm and the conductor leads from the sensors can be separately mounted and routed so that the sensor leads do not kink or interfere with the motion of the arm.

Abstract: A probe for aspirating and dispensing fluids is provided with a concave arcuate termination of the tubular bodywall forming a terminal orifice, in which the tip of the arcuate termination projects inwardly toward the tubular axis; the projection of the tip extends to a position at a distance in the range of approximately 1/4 to about 3/4 of the distance perpendicularly across the outside diameter of the bodywall.

Abstract: Apparatus for measuring progressively the absorbance changes of a large number of aliquots from a plurality of different samples. The sample introduction, testing instructions, aliquot preparation, reagent dispensing, absorbance measuring and data recording all can be accomplished in a continuous mode of processing. Stat and batch operation also can be accomplished. The aliquots are in an array of cuvettes which is advanced slowly along a circular path. Photometer means, preferably having several photometric detectors, are mounted in fixed orientation on a common support that advances rapidly along a similar circular path, such that radiation passing through each of the cuvettes is monitored many times by a specific photometric detector by the time that that cuvette completes one circuit of its path. The photometric detectors can operate at several different wavelengths. Many different chemical reactions can be monitored at the same time.

Abstract: Apparatus for measuring progressively the absorbance changes of a large number of aliquots from a plurality of different samples. The sample introduction, testing instructions, aliquot preparation, reagent dispensing, absorbance measuring and data recording all can be accomplished in a continuous mode of processing. Stat and batch operation also can be accomplished. The aliquots are in an array of cuvettes which is advanced slowly along a circular path. Photometer means, preferably having several photometric detectors, are mounted in fixed orientation on a common support that advances rapidly along a similar circular path, such that radiation passing through each of the cuvettes is monitored many times by a specific photometric detector by the time that that cuvette completes one circuit of its path. The photometric detectors can operate at several different wavelengths. Many different chemical reactions can be monitored at the same time.

Abstract: Apparatus for measuring progressively the absorbance changes of a large number of aliquots from a plurality of different samples. The sample introduction, testing instructions, aliquot preparation, reagent dispensing, absorbance measuring and data recording all can be accomplished in a continuous mode of processing. Stat and batch operation also can be accomplished. The aliquots are in an array of cuvettes which is advanced slowly along a circular path. Photometer means, preferably having several photometric detectors, are mounted in fixed orientation on a common support that advances rapidly along a similar circular path, such that radiation passing through each of the cuvettes is monitored many times by a specific photometric detector by the time that cuvette completes one circuit of its path. The photometric detectors can operate at several different wavelengths. Many different chemical reactions can be monitored at the same time.