Abstract: The present invention provides an apparatus for forming a mixture containing a regulated, low concentration of a target component within a carrier fluid. In accordance with the present invention, the carrier fluid is passed through the bed including a compound having two phases with one of the two phases containing the target component. A vapor phase of the target component exists within the bed in equilibrium with the target component contained within at least one of the two phases. The vapor phase has a partial pressure dependent upon bed temperature. The carrier fluid is then passed through the bed so that it contains the target component upon leaving the bed at essentially the partial pressure of the vapor phase. The target component concentration is dependent upon a quotient of the partial pressure of the vapor phase and carrier fluid total pressure. Regulation of the bed temperature and carrier fluid total pressure will in turn regulate the concentration of the target component within the carrier fluid.

Abstract: A control slide for use in an immunoassay having a section of a cell pellet retained on the slide in a stable and substantially permanent formation which can be stored at room temperature. Further, the invention includes the method of making the control slide.

Abstract: A method and reagent system are disclosed for the rapid isolation, identification and/or analysis of leukocytes from a whole blood sample. The method and reagent system of this invention has application to any environment in which the study and/or analysis of the leukocyte fraction of whole blood requires their isolation in their native or near native state. One of the environments in which this invention can be used to advantage is in the performance of white cell differentiation on automated instrumentation designed for that purpose. In one of the preferred embodiments of this invention, the lytic reagent can contain a mixture of both formic and acetic acid, with the formic acid comprising the major component thereof and the acetic acid being present in only minor quantities, (if at all). This reagent system is used to selectively effect stromatolysis of red blood cells and create subtle modifications to the leukocyte population to enable their automated differentiation into five (5) sub-populations.

Abstract: A reagent for and method of measuring leukocytes or hemoglobin or both in blood using a reagent which is water-soluble mixture containing:(a) a polyoxyethylene-based nonionic surfactant represented by the formula:R.sub.1 --R.sub.2 (CH.sub.2 CH.sub.2 O).sub.n --Hwhere R.sub.1 is an alkyl, alkenyl or alkynyl group having 6 to 24 carbon atoms, R.sub.2 is --O--, ##STR1## or --COO--, and n is an integer of 6 to 50, and (b) a buffer to adjust the pH of the solution within the range of 3-11 is disclosed. Measurements of hemoglobin in blood samples are of extreme importance to clinical diagnosis of such diseases as leukemia and anemia. Measurements of eosinophils, which are in the category of leukocytes, are important to the diagnosis of allergic conditions.

Abstract: The filtering apparatus is used in combination with at least one analytical instrument, especially a particle analyzer and substantially comprises a controlled pump unit having an inlet side and an outlet side. The inlet side of the controlled pump unit is connected to a reservoir for a liquid medium to be filtered. The outlet side is connected to a filtering unit. An intermediate storage unit for intermediately storing the filtered liquid medium is connected to the filtering unit. The filtered liquid medium is fed to the analytical instrument from the intermediate storage unit which contains level detectors for detecting the liquid level in the intermediate storage unit. The level detectors are connected to a control unit for controlling the controlled pump unit.

Abstract: A material and method are described to reduce the non-specific binding of a labelled material, wherein the labelled material comprises a fluorochrome and a specific binding pair member. The invention is particularlly suited to the lysis of peripheral blood wherein a labelled material is used to identify and detect cell populations within a sample of blood.

Abstract: A process for quantification of cell populations or subpopulations, by incubating a sample with labelled antibodies directed against characteristic surface antigens of the cell population to be quantified to form labelled antibody/antigen complexes. Standards with known, differing particle concentration and having comparable sedimentation behaviour to the cells to be determined and further, carrying molecules which are directed against the labelled antibody or a part hereof are also incubated with the labelled antibodies. The cells of the sample solution, as well as the particles of the standard solution, are separated off from the excess labelled antibodies and the amount of the labelling is measured not only on the cells but also on the particles. By comparison of the measurement value from the sample with the measurement values from the standard solutions, there is ascertained the number of cells to be determined in the sample.

Abstract: A kit of highly uniform size microbead standards for flow cytometer alignment, compensation, and/or calibration, comprising a blank microbead population and/or an auto-fluorescent microbead population, together with two or more series of calibrated microbead populations labeled with fluorescent dye(s) which (i) prior to fluorescent dye(s) labeling, match the fluorescence spectra and fluorescence intensity of the blank and/or autofluorescent microbead population, and (ii) after fluorescent dye(s) labeling, match the fluorescence spectra and fluorescence intensity of fluorescently labeled samples to be measured on the flow cytometer. Also disclosed is a corresponding method to align, compensate, and/or calibrate a flow cytometer so as to make measurements on samples comparable and independent of the specific instrument and instrument settings.

Abstract: A qualitative and quantitative method of determining the fluorescence threshold of an instrument and of determining whether the instrument is sensitive enough to measure the autofluorescence of a sample. The method utilizes non-fluorescent particles such a microbeads which are run on a flow cytometer. The peak channel position of the microbeads is used as the fluorescence threshold.

Abstract: The use of a combination of calibrated microbead populations with one or more calibrated biological cell populations to correct calibration of a flow cytometer for size and fluorescence intensity determinations of biological cell samples. The use of calibrated biological cells permits correction for factors related to the instrument and calibration microbeads so long as the excitation and emission spectra of the calibration microbeads, the calibration cells and the cell samples are all the same, respectively.

Abstract: Highly uniform microbeads containing a single fluorescence dye or a mixture of fluorescence dyes, which can be excited over a wide range of the spectrum extending from the ultraviolet to the infrared, and which can be used to align a flow cytometer or fluorescence microscope.

Abstract: A flow cytometer reference standard containing a highly uniform microbead population, wherein each microbead has the same multiple fluorescent labels as the other microbeads and as the samples to be measured. Target conditions are set for the sample after alignment of the flow cytometer. The microbead reference standard is used to determine peak channels (target channels) for each parameter. The target conditions may be reestablished for later uses of the flow cytometer with the same type of samples by using the microbead reference standard to adjust the flow cytometer so that the microbead peak channels fall in the originally determined target channels.

Abstract: In the method of this invention, dispensed volume is calculated from the ratio of the absorbance values for a sample delivered by a precisely calibrated pipette and the sample dispensed by an automated pipette. This links a gravimetric method of calibration to a colorimetric method.

Abstract: A method of lyophilizing mammalian cells to produce preserved human cells, hybridoma cell lines, tissue cells, and control cells for immunoassays and other hematological measurements. Prior to freezing and lyophilizing, the prepared mammalian cell pellet is suspended in a solution of trehalose in an isotonic fluid prepared at a specified optimal concentration and incubated at room temperature for a designated time period. The lyophilized cells when rehydrated, retain their optimal physiological characteristics suitable for use as an analytical control and retain said characteristics after storage at 2.degree.-8.degree. C. for a period in excess of five (5) months.

Abstract: A composition is disclosed of blood serum sample preparation for improved, more accurate and precise, electrooptical method for measuring erythrocyte volumes, individually and as an average.

Abstract: Lysable, blood platelet controls are prepared by treating animal red blood cells larger than or within the size range of human blood platelets with a fixing agent for red blood cells for a time sufficient to partially rigidify the red blood cell membrane enabling shrinking to a permanently shrunk condition, subjecting distinct groups of said partially fixed red blood cells to hemolysis wiht a hemolytic agent to partially remove hemoglobin therefrom, the hemolysis of each distinct group of cells removing a different amount of hemoglobin, subjecting the resulting red blood cells to centrifugation to collapse the red blood cell membrane around the hemoglobin remaining in said cells, said distinct group of cells and the extent of hemolysis being selected so as to provide after said centrifugation a mixture of permanently shrunken lysable cells that simulate in number, size and volume distribution the platelets present in human whole blood.

Abstract: This invention relates to a method for the rapid determination of a differential white blood cell count in a sample, which method comprises:(a) preparing a reagent solution comprisingformaldehyde or paraformaldehyde;a surfactant;a sugar or sugar alcohol; anda buffer; and(b) rapidly mixing the reagent solution with the sample to be analyzed to form a reaction mixture, wherein both the reagent solution and the sample are initially at room temperature; and(c) rapidly heating the reaction mixture to a temperature of from about 62.degree. C. to about 72.degree. C. in order to lyse the red blood cells in the sample and fix the white blood cells in said sample. The invention also relates to the reagent solution of part (a) of the method.

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.

Abstract: System for quantifying components in a liquid sample, for example white blood cells in blood, based on use of substantially non-compressible beads of uniform diameter as spacers between a microscope slide and cover slip. The distance between the slide and cover slip is determined by the diameter of the beads, and thus the volume of the sample being viewed can be precisely determined. Prior to use, the beads may be adhered to a microscope slide or stirring rod in a dried adhesive matrix which is soluble in the liquid sample to be examined.

Abstract: A method for calibrating a flow cytometer or fluorescence microscope in terms of number of binding antibodies as a function of fluorescence intensity value measured on the flow cytometer or fluorescence microscope, and subsequent measuring of a sample to which the antibodies are bindable. Also disclosed is a microbead calibration kit for carrying out the calibration method of the invention. The disclosed calibration methodology provides a direct relationship between instrument response and numbers of binding antibodies, independent of the fluorochrome employed to label the samples being measured. The method has utility in monitoring the status of an antigenic cellular condition in which the number of antibodies binding to successively obtained cellular samples is determined, to establish the progressionary character of the antigenic cellular condition, in a host from which the cellular samples are taken.

Abstract: A lysing agent and a method for utilizing the lysing agent in the identification and enumeration of cells of a select subclass of leucocytes is provided. The lysing agent includes formaldehyde, an alkali or alkaline earth salt of a weak acid and a polyhydric alcohol.

Abstract: Reticulocytes, RNA or DNA are stained with a dye for detection in a flow cytometer. The dye has the formula: ##STR1## Wherein: X=O,S, Se, N -alkyl (having 1-6 carbons) or C (CH.sub.3).sub.n ; R.sub.1 =alkyl having from 1-6 carbons;R.sub.2 =alkyl having from 1-6 carbons;R.sub.3 =fused benzene, alkyl (having 1-6 carbons), methoxy or is absent;R.sub.4 =alkyl having 1-6 carbons, methoxy or is absent; andn=zero or an integer from 1-6.

Abstract: A process for quantification of cell populations or subpopulations, by incubating a sample with labelled antibodies directed against characteristic surface antigens of the cell population to be quantified to form labelled antibody/antigen complexes. Standards with known, differing particle concentration and having comparable sedimentation behavior to the cells to be determined and further, carrying molecules which are directed against the labelled antibody or a part hereof are also incubated with the labelled antibodies. The cells of the sample solution, as well as the particles of the standard solution, are separated off from the excess labelled antibodies and the amount of the labelling is measured not only on the cells but also on the particles. By comparison of the measurement value from the sample with the measurement values from the standard solutions, there is ascertained the number of cells to be determined in the sample.

Abstract: A method of calibrating a flow cytometer or fluorescent microscope is based on a set of highly uniform microbeads associated with a fluorescent dye in such a way that the microbeads have the same excitation and emission spectral properties as the samples which are to be measured. The calibration values of the microbeads are plotted against the relative fluorescence intensity peak channel or intensity reading for each microbead in the set. From this calibration plot, the relative fluorescence intensity peak channel or intensity reading of the sample is translated into equivalent soluble fluorescent dye molecules per sample particle. The calibration values of the standard microbeads are determined against solutions of the dyes.

Abstract: A method for calibrating an instrument for using that instrument to obtain at least one light-related signal from particles under analysis comprises directing an incident beam of light at calibration particles having one or more known characteristics related to the particles expected to be analyzed. Both a light signal and a noise signal from the calibration particles are detected. A measurement is made of the ratio of the detected light signal to the detected noise signal, and that measurement is reported. The measured ratio is then compared to a predetermined ratio which represents a threshold for minimum instrument performance. This method further includes adjusting, if the predetermined ratio has not been attained, the operation of the instrument, while the calibration particles are within the incident beam of light, until the measured ratio reaches the predetermined ratio whereby the instrument is calibrated for subsequently obtaining the light signal from particles to be analyzed.

Abstract: A kit of highly uniform microbead standards for flow cytometer alignment, compensation, and calibration, comprising a blank and/or auto-fluorescent microbead population, together with two or more series of calibrated microbead populations which match the fluorescence spectra of labeled samples to be measured on the flow cytometer. Also disclosed is a corresponding method to align, compensate, and calibrate a flow cytometer so as to make measurements on corresponding samples comparable and independent of the specific instrument and instrument settings.

Abstract: Disclosed are a calibrator composition and method of producing and using the same in the analysis of blood of a particular species. From whole blood of the particular species, a solution is derived with which semi- and fully-automated particle counters can be calibrated to count cells in the size range appropriate for the particular species.

Abstract: A control slide for use in an immunoassay having a section of a cell pellet retained on the slide in a stable and substantially permanent formation which can be stored at room temperature. Further, the invention includes the method of making the control slide.

Abstract: This invention relates to a method for the rapid determination of a differential white blood cell count in a sample, which method comprises:(a) preparing a reagent solution comprising;formaldehyde or paraformaldehyde;a surfactant;a sugar or sugar alcohol; anda buffer; and(b) rapidly mixing the reagent solution with the sample to be analyzed to form a reaction mixture, wherein both the reagent solution and the sample are initially at room temperature; and(c) rapidly heating the reaction mixture to a temperature of from about 62.degree. C. to about 72.degree. C. in order to lyse the red blood cells in the sample and fix the white blood cells in the sample.

Abstract: Red cells are exposed to an unsaturated aldehyde such as acrolein (propenal) under conditions sufficient to increase the stability of the cells without impairing the ability of a lysing reagent to lyse the cells. After treatment, the treated cells are washed and are suspended in a stabilizing suspension medium.

Abstract: A method of calibrating a flow cytometer or fluorescent microscope is based on a set of highly uniform microbeads associated with a fluorescent dye in such a way that the microbeads have the same excitation and emission spectral properties as the samples which are to be measured. The calibration values of the microbeads are plotted against the relative fluorescence intensity peak channel for each microbead in the set. From this calibration plot, the relative fluorescence intensity peak channel of the sample is translated into equivalent soluble fluorescent dye molecules per sample particle. The calibration values of the standard microbeads are determined against solutions of the dyes.

Abstract: A method of calibrating a flow cytometer is based on a set of highly uniform microbeads associated with a fluorescent dye in such a way that the microbeads have the same excitation and emission spectral properties as the samples which are to be measured. The calibration values of the microbeads are plotted against the relative fluorescence intensity peak channel for each microbead in the set. From this calibration plot, the relative fluorescence intensity peak channel of the sample is translated into equivalent soluble fluorescent dye molecules per sample particle. The calibration values of the standard microbeads are determined against solutions of the dyes.

Abstract: This invention describes a reagent system, including saponin in a lysing reagent and a rapidly active cross-linking agent such as glutaraldehyde as a fixing reagent, which reproducably affects whole blood to cause the red blood cells to stromatolyze and modifies the leukocytes to generate data to define four distinct clusters for detection and classification by flow analysis instrumentation. The clusters represent the four major leukocyte types found in blood: lymphocytes, monocytes, neutrophils and eosinophils, thus providing a method of leukocyte differential analysis. The parameters used for the leukocyte classification include combinations of two or more of DC (Coulter) volume, high frequency (RF) size, opacity (RF size/DC volume), light scatter at various angular ranges, and fluorescence at various wavelengths of illumination.

Abstract: For the simultaneous quantitative determination of the blood cells or other ells, the cell blood sample is incubated with a fluorescent stain cocktail containing fluorescent dyes and calibration particles and which stains at least one characteristic of the blood cells, and then the volume and the fluorescence of the cells and particles are measured simultaneously at at least one wavelength.

Abstract: A whole blood control sample and a method of preparing the sample are disclosed. The method comprises collecting a whole blood sample from one or more donor, separating each sample into red blood cells and plasma, fixing the red blood cells, mixing the fixed red blood cells with plasma from the same or a different donor to produce a suspension, quick-freezing the suspension before the red blood cells can settle, and lyophilizing the frozen suspension. The control sample therefore comprises a lyophilized mixture of fixed red blood cells and plasma solids.

Abstract: A stable glucose reference control has been found in which the true value and the measured value of glucose in blood, colorimetrically obtained with glucose test strips, is approximately the same. The glucose reference control comprises an aqueous suspension of:(i) 40 to 500 mg/dL of glucose, and(ii) about 0.1 to 0.3.times.10.sup.12 /dL red blood cells fixed with a fixing agent to render the red blood cells incapable of metabolizing glucose.

Abstract: Disclosed are a calibrator composition and method of producing and using the same in the analysis of blood of a particular species. From whole blood of the particular species, a solution is derived with which semi- and fully-automated particle counters can be calibrated for the particular species.

Abstract: A method of calibrating a flow cytometer or fluorescent microscope is based on a set of highly uniform microbeads associated with a fluorescent dye in such a way that the microbeads have the same excitation and emission spectral properties as the samples which are to be measured. The calibration values of the microbeads are plotted against the relative fluorescence intensity peak channel for each microbead in the set. From this calibration plot, the relative fluorescence intensity peak channel of the sample is translated into equivalent soluble fluorescent dye molecules per sample particle. The calibration values of the standard microbeads are determined against solutions of the dyes.

Abstract: This invention primarily is directed to a hematology reference control solution, the three separate white cell control portions thereof consisting of three types of fixed red cells of determined size distribution for checking the operation of a particle analyzing instrument, including its predetermined lower and upper threshold settings for each class or subclass of leukocytes.For preparing a human granulocyte analogue, nurse shark erythrocytes are altered and fixed in a chilled solution to simulate in number, size and distribution the granulocytes in human whole blood.

Abstract: A device is described for preparing a standardized concentration of washed particles suspended in a fluid. The preferred method is directed to the preparation from whole blood specimens of a standardized concentration of washed red cells in isotonic solution using a device comprising a test tube formed at the bottom end with a nipple-like receptacle having a predetermined volumetric capacity. Whole blood is mixed with isotonic solution in the device which is then centrifuged causing the red cells to be first washed and then packed into the receptacle. The liquid contents of the device are then decanted without disturbing the packed red cells. Thereafter, the red cells are reconstituted to the desired concentration by adding isotonic solution to a predetermined level in the tube and mixing the cells into the isotonic solution.

Abstract: Blood cells such as erythrocytes of animal origin are treated with a solution containing water, an organic cosolvent (such as dimethylsulfoxide, alone or admixed with a polyol), an aromatic polyaldehyde (such as phthaldialdehyde) and optionally salts and buffers. In an illustrative case, the treating solution is hypertonic and shrinks goat erythrocytes to the size of human platelets.

Abstract: A method of lyophilizing reagent-coated latex particles which results in a product easily reconstituted without agglutination, retains activity, and remains stable and active at storage at 4.degree. C.

Abstract: A reagent for blood analysis comprises, as a lysing reagent for leukocyte count, tetradecyltrimethylammonium bromide and/or hexadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, and citric acid. This reagent is characterized by showing three-peaks fractionation of leukocytes in measuring by means of an automatic blood-analysis instrument. The lysing reagent is used together with a diluent comprising boric acid buffer solution, ethylenediaminetetraacetic acid and (2-pyridylthio-1-oxide) sodium.

Abstract: A lysing agent and a method for utilizing the lysing agent in the identification and enumeration of cells of a select subclass of leucocytes is provided. The lysing agent includes formaldehyde, an alkali or alkaline earth salt of a weak acid and a polyhydric alcohol.

Abstract: Lysing reagents for use in flow cytometry instruments. Lysing reagents suitable for lysing red blood cells are provided thereby permitting 3-part differential counting of white blood cells. The reagents comprise a leukoprotective agent for preserving the lymphocyte cellular integrity during analysis, and buffers adjusted to provide the correct pH environment for optimal lysis and activity. Preferred embodiments will additionally incorporate non-ionic preservatives in very low concentrations.

Abstract: A preservative solution for fixed avian erythrocytes for the viral hemagglutination test of this invention comprises purified water which may contain serum albumin, glycerol or dimethyl sulfoxide and, additionally, a preventive against the growth of bacteria as occasion demands. Fixed avian erythrocytes can stably be preserved in this solution. HA and HI test can precisely be performed by employing fixed avian erythrocytes suspended in this invention.

Abstract: A reagent for blood analysis comprises, as a lysing reagent for leukocyte count, tetradecyltrimethylammonium bromide and/or hexadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, and citric acid. This reagent is characterized by showing three-peaks fractionation of leukocytes in measuring by means of an automatic blood-analysis instrument. The lysing reagent is used together with a diluent comprising boric acid buffer solution, ethylenediaminetetraacetic acid and (2-pyridylthio-1-oxide) sodium.

Abstract: A hematology control is disclosed which is useful for clinical hematology procedures and, in particular, mean corpuscular volume (MCV) determinations. The hematology control comprises an aqueous suspension of red blood cells in which varying levels of MCV are provided by applying to the red cell component, after light treatment with aldehyde, an osmotic pressure that is directly proportional to the desired red blood cell size.

Abstract: A rapid one step, one reagent method is disclosed for the isovolumetric sphering and fixing of whole blood erythrocytes.

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.