Abstract: A liquid diluting and transfer valve has disc like valve elements provided with faces frictionally engaged. The valve further includes passageways for passing both sample liquid and rinse liquid and a continuous groove formed in one of the respective faces. This continuous groove effectively isolates the passageway openings to the faces and is capable of blocking passage of leakage material along the face to the periphery of the engaged face.

Abstract: Water soluble xanthylium derivative substrates of rhodamine 110 and rhodol permit spectrophotometric and fluorescent measurements of trypsin-like enzymes without the addition of organic solvent additives and/or special water solubilizing agents. These novel substrates exhibit increased sensitivity for determining low levels of activity of trypsin-like enzymes such as proteolytic enzymes, cofactors, activators, antiactivators, and inhibitors. These substrates can be substituted for fibrinogen or monitor the pathways of blood coagulation.

Abstract: An apparatus for dislodging fragile particles, such as intact biological cells, retained by the separation matrix in a flow chamber of a magnetic separation system. The apparatus incorporates a piezoelectric transducer which is coupled to the matrix and an associated drive circuit. The system can operate in a capture phase, whereby fragile particles are selectively captured from a carrier fluid passing through the matrix, with those captured particles being magnetically held in place within the matrix. In the elutriation phase, an elutriation fluid is passed through the matrix and the drive circuit excites the piezoelectric transducer. In response to the excitation, the transducer establishes acoustic waves in the elutriation fluid passing through the matrix, vibrating the matrix itself. Depending upon the mechanical impedances within the flow chamber, the acoustic waves can be ultrasonic.

Abstract: A system for the magnetic separation of fragile particles, such as intact biological cells, from a fluid medium. The system includes at least one high-gradient magnetic separator having a flow chamber housing an interstitial separation matrix and associated magnetizing apparatus for coupling magnetic flux to the matrix. The matrix has interstices through which a carrier fluid carrying the cells-to-be-separated may be passed. The magnetizing apparatus includes opposing North and South poles and field-guiding pole pieces, external to the flow chamber. The flow chamber comprises a dual-position flux-coupler. The flux-coupler is operative in a first position in the capture phase and in a second position in an elutriation phase. In the capture phase, the flux-coupler is positioned to permit the magnetic flux from one magnetic pole to pass through the matrix to the other magnetic pole.

Abstract: A molded flexible fluid conduit and a make/before break pinch valve including a slidably movable pressure member spring biased normally against said conduit in closed condition of the valve, said conduit including a pair of elongate longitudinal unitary purchase formations capable of cooperating with slots carried by the valve whereby the conduit forcibly is pulled or stretched in diametrically opposed directions upon actuation of the valve subsequent to periods of closure so as to force the conduit open to permit flow.

Abstract: A shipping and storing support having recesses so constructed and arranged to ship and store selectively a plurality of articles having varying dimensions, the recesses having a plurality of internal contours for selectively receiving the articles to be retained therein by a frictional fit and wherein the plurality of internal contours of the recesses have substantially the same contour as a portion of the plurality of different sized articles adapted to be received frictionally in said recesses.

Abstract: A particle analyzing apparatus and method of moving and counting particles in suspension through such an apparatus. The particle analyzing apparatus comprises a particle counting device wherein particles in suspension are caused to be moved through an aperture whose effective impedance is changed with the passage of each particle therethrough and a fluid connection means for drawing a quantity of the suspension through the aperture, including a source of vacuum. The source of vacuum comprises a bellows having an end, and a constant force means connected to the end of the bellows means.

Abstract: A plurality of sealed blood sample tubes are housed in a rack and a plurality of these racks are vertically stacked, with the sample tubes lying horizontally. The racks are successively deposited onto a horizontal conveyor belt which is housed in and moves longitudinally on a table that rocks around its longitudinal axis to mix the samples in a semi-inverting mode as a rack is stepped from the stack to a sample aspiration station and/or thereat. The aspiration station preferably includes a sample segmenting and diluting valve and a sample identification reader. Aspiration is accomplished by pushing a sample tube partially out from the carrier rack and onto a seal piercing tip of the aspiration probe. The tube then is returned to the rack. The other tubes in that rack similarly are aspirated after the rack is stepped to align each tube with the aspiration probe, with table rocking and sampling mixing accompanying each advancing step of the rack.

Abstract: Disclosed is an inductance detector for detecting boundaries between and characteristics of at least two adjoining substances having different characteristics, such as impedance, wherein a coil assembly, which is energized by an alternating current, is electrically coupled to a detector for detecting at least changes in impedance of the coil assembly caused by the boundary proceeding into and through the coil assembly.

Abstract: Offset-error included data normally is output from a single ramp analog to digital converter in response to input information applied thereto during light or cuvette sample intervals. During dark sample intervals between the cuvette sample intervals, the input information is blocked from the converter and the converter is operated with the output counter counting down to a dark count representing the offset error of the counter. During the next cuvette sample interval the counter counts up from the dark count effectively subtracting out the offset error introduced by the converter.

Abstract: A two-reagent assay system for determination of gamma glutamyl transpeptidase enzyme activity in a biological fluid. Gamma glutamyl-p-nitroanalide substrate for the enzymatic reaction is provided in a first reagent which is a dry mixture of the substrate with a normally solid acid which is water soluble and a second reagent includes a buffer and a component selected for reception of the glutamyl product of the enzymatic reaction.

Abstract: An optical microscope system includes an optics system and a frame. A selectively controlled stage assembly is coupled to the frame by vacuum-retained air-bearings. An air vacuum chuck coupled to the stage selectively aligns and supports an object-bearing slide for viewing with the optics system.

Abstract: A stackable cassette or rack for supporting a plurality of sealed sample containers having different diameters and/or lengths and transporting the same to a testing station of a hematology analyzer device. The cassette comprises a body having a top and a bottom and a rear portion, and the body includes a base, front and intermediate walls and a biasing means, connected between the front and intermediate walls, both walls longitudinally extend across the base and each wall has a plurality of equidistantly spaced openings therein arranged in a row lengthwise of the cassette which openings extend from the base to the top of the body. Each of the openings in the front wall has an upper edge and the spaced apart holes of both walls are in alignment.

Abstract: Disclosed is a method wherein osmotic activity of biological cells immersed in a suspension solution is induced by an osmotic or lytic shock and is monitored in an electronic volume sensing particle analyzer of the Coulter Counter.RTM. type, the method including the steps of passing a high frequency current and a low frequency current through an aperture of said particle analyzer to create detectable signals for classifying the cells into populations of unaltered, altered, and ghost cells.

Abstract: An improved reagent provides combined diluting and lysing of whole blood for use in instruments performing electronic blood cell counting and hemoglobin determination. The reagent prevents platelet aggregation and improves the accuracy of the white blood cell count.

Abstract: A method and reagent system is described for differential determination of more that one class of leukocyte populations, using an automatic blood cell analyzer. The reagent system includes a blood diluent and stromatolyzing reagent. The blood diluent is an osmotically balanced aqueous solution of ingredients for maintaining erythrocyte morphology, blood cell stabilizing, buffering and bacteriostatic action. The stromatolyzing reagent is a mixture of an aqueous solution of quaternary ammonium salts, a chromagen forming agent and an additive which is a non-cationic surfactant. The quaternary ammonium salts, with the additive, serve the purpose of positioning, relative to one another and a volume reference point, the lymphoid and myeloid populations. The additive also acts to prevent or to reduce the amount of protein deposit in the sensing orifices of the analyzer, which deposit tends to accumulate from the cell debris resulting from blood cell stromatolyzation.

Abstract: A particle analyzer apparatus comprising a flow cell having a flow chamber wherein a flow of liquid suspension, having individual particles entrained therein, proceeds along a predetermined path; a pair of electrodes are disposed on opposed sides of the predetermined path, one of the electrodes having an end with a width parallel to the predetermined path that is less than the length of a given particle, the end of the electrode being positioned in close proximity to the predetermined path; energizing source for providing an electrical field between the pair of electrodes that traverses the predetermined path; and a particle pulse detector for detecting particle pulses caused by the particles passing through the electric field.

Abstract: A particle analyzing apparatus for studying a stream of membrane-sheathed particles in liquid suspension wherein, for a given particle, a first particle pulse signal is obtained from a first sensing aperture having a first low frequency electrical field with an intensity below that causing particle electrical breakdown; a second particle pulse signal is obtained from a second sensing aperture having a second low frequency electrical field with an intensity equal to or greater than that causing particle electrical breakdown; a third particle pulse signal is obtained from one of the sensing apertures by having a high frequency electrical field therein or, alternatively, from a third sensing aperture having a third low frequency electrical field with a second and different intensity equal to or greater than that causing particle electrical breakdown.

Abstract: In an apparatus in which particles which may include biological cells are passed through an optical sensing zone to measure their spatial radiant energy distribution for the purpose of identifying and/or characterizing the particles or cells, a structure and method are provided for increasing the usefulness of a geometric configuration of photovoltaic detectors such as a known assembly of generally concentric rings of such detectors usually including some wedge-shaped detectors. These are provided in a generally planar form and the invention provides structure which captures radiant energy in a flow cell of a particular type before projecting the energy to the detector. In particular an ellipsoid, paraboloid, hyperboloid or similar reflector which is symmetrical about its optical axis is utilized first to capture the radiant energy on angles which could include most forward and/or backward angles and all azimuthal angles and then deviating the same to the detector assembly mentioned.

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, and dimethylolurea which, together with the ADA, allow preferential determination of myeloid-lymphoid leukocytes, and other hematological values.The lysing agent is a mixture of an aqueous solution of at least one quaternary ammonium salt having surface active properties, and an alkali metal cyanide.