Abstract: Reagent and reagent mixtures useful for detecting and measuring total bilirubin concentrations in biological liquids such as serum and methods of assaying biological liquids using such reagents are disclosed.

Abstract: A liquid substance is transferred from a first carrier stream to a second carrier stream. The transfer includes the use of a movable conveyor and the flow of a deposited volume of the first stream along a portion of the conveyor as a sheath stream.

Abstract: Method and apparatus for casting a metal article in a mold at least as long as the article, utilizing a cooled mold of elongated form having top and bottom portions. The method includes the steps of introducing molten metal from a source through the bottom portion of the mold, flowing molten metal into the mold so as to form a solidifying casting shell which during casting occupies at least 40% of the cross-sectional mold area and has a molten core, and flowing molten metal from the source through the core towards the mold top.

Abstract: Method and apparatus for the determination of the instantaneous flow velocity of a segmented fluid stream in an optically transparent conduit are disclosed, and comprise light-sensitive flow signal generation means operatively associated with said conduit and operable to generate a signal including a characteristic which is representative of said instantaneous flow velocity, and flow signal processing means which are operable to detect said characteristic and provide a signal indicative of said instantaneous flow velocity.

Abstract: Procedures are disclosed for obtaining white blood cell counts and platelet counts by light scattering measurements in which anticoagulated blood samples are treated such that the morphology of the white cells (leukocytes) and platelets remain intact and permit the discrimination of platelets from white cells and of most classes of white cells from one another and their counting without the need for staining.

Abstract: A method for determining a volume of red cells in a blood sample. The method includes the steps of flowing along a conduit a predetermined volume of the sample, introducing an agglutinating reagent and a predetermined volume of a dye into the conduit to mix with the sample and agglutinate the red cells, the dye being of known concentration on the introduction thereof, decanting the agglutinated red cells from the conduit, and colorimetrically measuring the concentration of the dye in the conduit, the agglutinating reagent being characterized by a relatively high positive electrical charge and the dye being water soluble and characterized by not penetrating said cells and not forming a precipitate with the agglutinating reagent or with the soluble components of the sample and not lysing the cells or altering the volume of the cells.

Abstract: A method, for microcoulometric determination either of the activity of an enzyme in a liquid sample or the concentration of a substrate for a reaction involving a change in a coenzyme from a first form thereof to a second form. At intervals during the reaction, both coenzyme forms are measured essentially simultaneously utilizing an electrolytic cell, to indicate either such enzyme activity or substrate concentration, depending upon which is the unknown factor.

Abstract: A multichamber cuvette for maintaining in independent and separate condition at least two reactants until such time that it is desired to mix them for reaction with each other and a reactant liquid sample for analysis in the cuvette. There is provided a cuvette body of a suitable plastic defining at least two chambers interconnected by a passageway of relatively small cross section having at least the end portions thereof of capillary size to prevent under many circumstances, as by surface tension, accidental mixture of liquid reactants in the chambers. If there is a substantial head of liquid in one chamber and/or a risk of impact of the cuvette with an external foreign object, sufficient to break such surface tension, an air lock in the passageway when the latter is below the liquid levels in the chambers prevents such accidental mixture. A baffle in the passageway enhances separation of liquids and/or solid substances in the chambers.

Abstract: Method and apparatus for improved optical discrimination in a total particle population of particles having a significant light absorption characteristic and particles having a significant light scattering characteristic. There is provided in such a method a combination of steps including, directing a beam of light from a source to transversely illuminate at an optical interaction station particles passed one by one through such station, partially obstructing the beam beyond the station for passage of scattered and unscattered portions of the beam, when a particle is in said beam and detecting one of said beam portions.

Abstract: A sampler is provided having a liquid sampling probe. A drive mechanism for the probe includes a screw element and a nut element threaded thereon, one of which elements is axially fixed and driven to axially raise and lower the other element which supports the probe. In one axial position of the element supporting the probe, the last-mentioned element is moved between first and second angular positions thereof.

Abstract: Method and apparatus are provided for the determination of the Raylographic information of a body part which is ensonified by acoustical energy pulses by a particularly precisely focused acoustical focusing system to produce acoustical energy echo pulses which are detected in coherent manner. Fourier transformation of the pulses from the time to the frequency domain enables frequency domain deconvolution to provide the impulse response with minimization of mathematical instabilities and distortion of the frequency domain impulse response. Noise extraction and spatial deconvolution filtering are included to respectively maximize signal to noise ratio and minimize distortive effects of body part surface non-orthogonality and combine with the above to provide for particular stability in the overall results and attendant increase in the axial resolution of Raylographic display and in the overall resolution of body part image displays.

Abstract: A method for analyzing a biological fluid sample for Ab, Ag, or Ab:Ag complexes therein which includes the step of adding to the sample a solution of RF or Clq to bind with Ab:Ag complexes present or formed therein, and thereafter analyzing the mixture so formed for complexes bound to RF.

Abstract: This invention relates to the use of derivatives of N-1-naphthyl ethylenediamine for standardization of direct bilirubin assays.

Abstract: Apparatus and method for obtaining a concentration gradient in a liquid sample analyzer including flowing a first liquid in a stream to fill a conduit, and continuing the flow of the first liquid along the conduit subsequent to the filling step. Combined with these steps is the step of changing the concentration of the first liquid by removing from the stream a predetermined varying volume of the first liquid and adding to the stream a predetermined proportional varying volume of a second liquid. There is also provided a method of serial dilutions of a liquid stream in a conduit by removal of a portion of the stream prior to each diluent addition for the purpose of conserving diluents which may be reagents.

Abstract: A standard, which is of ceramic material and preferably includes alumina, for spectral reflectance for use in near infrared reflectance measurements of constituents of samples, which constituents comprise oil, moisture and protein. The standard reflects electromagnetic radiation in the wavelength range of 1.0 - 2.5 micrometers and exhibits its best optical characteristics in the operational range of 1.4 - 2.4 micrometers.

Abstract: A multichamber cuvette for maintaining in independent and separate condition at least two reactants, one of which may be a sample, until such time that it is desired to mix them for reaction with each other for photometric analysis in the cuvette. At least one of the chambers has a pair of optical quality windows aligned with one another for analysis of the then liquid contents extending between the windows. The cuvette body is of upright construction, defining at least two such chambers laterally of one another, open at the top for filling separately or simultaneously, and interconnected adjacent their lower extremities by a passageway of inverted U shape. The passageway is of an effective height exceeding the highest filling level of each chamber by a distance at least as great as any capillary rise in the passageway beyond such level of the particular liquid in that chamber.

Abstract: Blood is preserved by combining samples with a preservative reagent consisting of an aqueous mixture of a mono-, di- or trisaccharide component and formaldehyde.

Abstract: Apparatus and a method of separating a particulate portion as defined herein from a mixture including a liquid portion, including introducing the mixture into a stream of wash solution flowing along an open bore of a conduit, the wash solution having immiscible fluid segments therein, and subsequent to a separating step, collecting at least one of the aforesaid portions. Combined with these steps is the step of permeating over a period of time the internal surface of the aforementioned conduit with at least the aforementioned liquid portion. This retards the flow of the liquid portion which progressively lags behind the particulate portion until the two portions are separated by the segmented wash solution. Either or both portions may be collected, and when collected, the particulates are in washed condition.

Abstract: Apparatus for preparing a smear of a biological fluid substance containing cellular material on a first element having a surface for receiving the smear, utilizing a second element coacting with the first element. The elements are supported so that at least portions thereof are in close proximity to one another at a sample-applying station. A relatively small quantity of such biological liquid sample is introduced between the aforementioned element portions at the sample-applying station for spreading of the sample across at least the central portion of at least one of the aforementioned elements. The sample is spread or smeared on the aforementioned surface of the first element by moving one of the elements relatively to the other. The sample is mixed at least during the drawing of the sample so as to obtain a random distribution of such cellular material and enhance spreading such cellular material in a direction normal to the drawing of the sample.

Abstract: An article for drawing a blood specimen comprising a specimen-receiving tube having a closed end and an open end, a resilient expandable plug received in the closed end portion of the tube in normally relatively light sealing engagement with the side wall structure of the tube, and an elongated cannula holder having a through longitudinal passageway for communication with the interior of the cannula, the plug and the holder having co-acting means for releasably coupling the plug and the holder when the holder passageway is in communication with the closed end portion of the tube through the plug, the holder expanding the plug into relatively firm sealing engagement with the tube side wall structure. The holder may be uncoupled from the plug when the tube is filled with the specimen and the plug occupies the open end of the tube. The tube and its contents including the plug may be placed in a centrifuge.