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: 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.

Abstract: Method and apparatus for fluid supply for a continuous-flow analysis system which apparatus includes conduit means passing a stream segmented by an immiscible fluid, and a tube having an inlet portion movable out of and into an operative position a distance within the conduit in an upstream direction and being of a cross-sectional dimension which does not occlude the conduit.

Abstract: Apparatus and method for analyzing successive liquid samples and conserving reagent. The method includes flowing a stream of discrete samples along a conduit from a source, which conduit includes a portion for reacting the successive samples with a reagent and a portion for analyzing the reaction product. It further includes introducing the reagent into the conduit upstream of the reaction portion to form a sample-reagent mixture, identifying the successive samples at the source, and responsive to such identification discontinuing the introduction of the reagent into the conduit and substituting therefore a pilot fluid displacing the mixture at the same flow rate along the reacting and analysis portions of the conduit.

Abstract: Apparatus and method for analyzing liquid sample comprising flowing a stream including a liquid continuously in a conduit, detecting a flow rate characteristic in the conduit and generating a signal in response thereto, and increasing, decreasing or maintaining, unchanged the flow rate of the stream in the conduit in response to the signal, the flow being increased or decreased by the flow into the conduit of another fluid without changing the concentration of the aforementioned liquid. The continuing flow of the liquid may be the flow of a segmented sample-reagent liquid, and the other fluid which is added may be a gas.

Abstract: Method and apparatus for photometric analysis of sample fluids for a constituent of interest. There is provided a method of sample analysis comprising the steps of locating the sample fluid in a cell having an axis, directing a ray of light through the sample and the sample-cell interface at an angle to said axis, totally internally reflecting said light ray passed through the interface to be redirected across said sample, and detecting the redirected light ray passed through the sample.

Abstract: Apparatus and method, utilizing an ion-selective electrode and a reference electrode, for determining the percentage volume of total particulates in a predetermined volume of a liquid medium or sample having an effective known concentration of a particular ion. The method includes introducing a predetermined volume of a diluent having a known concentration of that ion into the sample, and measuring with the electrodes the concentration of that ion in the diluted sample to indicate the percentage volume of total particulates in the sample. The apparatus and method for such determination are well suited for determining the percentage volume of total cells in a sample of whole blood.

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 while in the cuvette for analysis in the cuvette, and a method of use of such 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: Apparatus and method for preparing a smear of a biological fluid substance on a substrate, utilizing a ribbon having relatively small openings in at least one surface thereof which openings are of substantially uniform size and are arranged substantially uniformly both longitudinally and transversely of the ribbon throughout at least a portion of the ribbon. The method includes the steps of supporting the substrate for movement and supporting the ribbon by a support in close proximity to the substrate at a substance-applying station, for a run of the ribbon past a portion of the substrate. Further steps include introducing a relatively small quantity of the aforementioned substance between the aforementioned ribbon surface portion and the substrate at the substance-applying station to spread by capillarity in a direction transversely of the ribbon, and moving the substrate in a direction to smear the substance on the substrate.

Abstract: A method for separating a blood cell portion and a liquid portion of a whole blood sample comprising the steps of contacting over a period of time a substance in the form of a nonparticulate gel mass with the sample, so as to diffuse the liquid portion into the mass, the mass having an effective pore size to exclude the blood cells, and collecting the blood cells remaining after such contact of the sample with the mass. The method may include impregnating the substance of the mass with a selective reagent to react with the liquid portion diffused therein, and furthr include analyzing a reaction product produced within the mass.

Abstract: A fluid sampler which may be held in the hand in the manner of a pencil is provided with an overstroke so that after a plunger is operated with a certain stroke to sample a determinable amount of fluid, the plunger can then be operated with an overstroke to make certain that all fluid is discharged from the sampler. The stroke of the plunger is furthermore adjustable. The sampler is provided with a longitudinally extended portable body provided with a bore extending longitudinally therethrough. A nozzle is provided at one end of the bore within which is a chamber. A plunger is located partly in the chamber and partly in the bore with a piston being operatively associated with the plunger and slidable in the bore. An adjustable control is provided in the bore to adjust the stroke of the piston. A lever is mounted on the body to operate the plunger through the intermediary of the piston whereby fluid may be drawn into or discharged from the aforementioned chamber.

Abstract: New and improved apparatus is provided for the calibration and standardization of the analog output signal level of automated analysis equipment, which level varies as a function of the concentration of the constituent being analyzed. Such apparatus comprises an A/D converter including a dual-slope integrator for translating the output signal level to a time interval which varies as a function of the constituent. Such apparatus further includes means for generating the inverse function of the analytical function, which is applied to linearize and scale the output signal level and to convert such level directly to digital form. Also, provision is made for the calibration and standardization, on an individual basis, of each of a plurality of analytical channels in a multi-channel system.

Abstract: Apparatus and method for photometrically analyzing a constituent of interest in body or other fluids and well suited for kinetic determinations which are temperature-and-time dependent. There is provided a sample holder holding a cuvette supporting a liquid sample and other reactants among which is a trigger reactant to initiate the reaction which is analyzed. The trigger and the other reactants are initially isolated in the cuvette.

Abstract: Method and apparatus for continuously casting metal tubing, utilizing an oscillatable mold, which lends itself to the casting of tubing of relatively large internal diameter. Molten metal is poured directly into the mold having a chilled axial wall structure, and then a starting bar, having at least an annular end portion immersed in the molten metal in the mold, is moved relatively to the mold to withdraw the solidifying cast metal tubing adhering thereto, during oscillation of the mold, the molten metal for such tubing being supplied from the mold. The supply of molten metal in the mold may be replenished by pouring additional molten metal directly into the mold through the annular starting bar without contact of the molten metal with either the starting bar or the solidifying tubing prior to the entry of such molten metal into the mold.

Abstract: Apparatus is described for treating substances carried or affixed to a surface of a continuous substrate, e.g., a ribbon or tape, with successive treating fluids including liquids contained in a series of treating chambers, adjacent chambers being separated by a high surface tension liquid, e.g., mercury. The chambers may be defined by hollow walls having slots located below the level of the treating fluids in the adjacent treating chambers, such slots being dimensioned to allow passage of the tape between the adjacent treating chambers and to prevent dislocation of the high-surface tension liquid, which is located in the hollow walls and serves to wipe excess treating fluid from the tape during passage between the adjacent treating chambers, so as to prevent carryover therebetween.

Abstract: An aspirating probe which has a travel from a lower position in which it is immersed in a liquid in a receptacle to an upper position in which it clears the receptacle, carrying with it in its movement to the upper position a washing device to wash the interior and exterior thereof when in the last-mentioned position.

Abstract: A quantitative liquid sample analysis system exhibiting improved light transmission along the sight path of a flowcell and greater optical stability for significantly more accuracy of analytical results. There is provided in such a system a source of treated liquid having a first index of refraction, means for flowing the liquid along a conduit, the conduit including a flowcell having a tubular wall structure with a second index of refraction, the second index of refraction being less than the first index of refraction.