Abstract: A method of normalizing surface tension of a sample fluid on a clinical analyzer is disclosed. The method comprises aspirating a portion of a sample fluid into a metering tip, the metering tip having a lower end through which the sample fluid is aspirated and an upper end; sealing the lower end of the metering tip, forming a cuvette for the portion of the sample fluid; pre-treating a micro-tip with a surface tension-normalizing agent, and then dispensing the surface tension-normalizing agent into the sample fluid in the cuvette; mixing the surface tension-normalizing agent and the sample fluid in the cuvette using the micro-tip to create a mixture of the sample fluid and the surface tension-normalizing agent, the mixture having a normalized surface tension; and using the mixture for testing on the clinical analyzer.

Abstract: This invention relates to an improved procedure for the multiparameter analysis of leukocyte subpopulations from peripheral blood, bone marrow or any body fluid containing blood nucleated cells, including the quantification of each subpopulation in terms of cells per microliter. The method uses a cocktail of at least four monoclonal antibodies labelled each with a different fluorescent tag, the measurement of at least two light scatter and four fluorescence emissions related parameters and at least one population of fluorescent beads to differentiate and enumerate between and among the different leukocyte subpopulations in the peripheral blood, the bone marrow or other body fluid.

Abstract: A whole-blood-based substitute composition that is useful in coagulation assays as a standard, reference, control, calibrator, linearity verifier, or training material is prepared by combining a red blood cell lysate that is free of plasma, leukocytes, and platelets with a platelet-free plasma of human origin and an antimicrobial agent.

Abstract: A sample preparation method is disclosed for volatilization and mass spectrometric analysis of nonvolatile high molecular weight molecules. Buffered aqueous solutions of matrix at near physiological pH are disclosed for use in Matrix-assisted Laser Desorption and Ionization (MALDI). The new methods expanded the application of MALDI to study non-covalent protein complexes.

Abstract: Automated staining equipment that can mix reagents is used to spray a Romanowsky stain onto slide mounted specimens which are then briefly centrifuged. The centrifugation step removes excess stain leaving only a thin film. Depending on the time of the centrifugation step, most of the organic solvent and part of the water in the stain are evaporated by airflow through the equipment. This greatly accelerates the staining reaction and preserves water soluble structures such as the granules in basophilic leukocytes. For optimal performance, this staining procedure requires a thiazin-eosin stain with about 90% to about 40% organic solvent, such as methanol, and only about 10% to about 60% water. This is a unique staining reagent in Romanowsky staining.

Abstract: The objects of the present invention are to solve low test efficiency and low accuracy which are problems encountered in the conventional methods for testing myelotoxicity of a drug by observing smears. To this end, markers for discriminating and identifying hematopoietic stem cells and blood cells at various differentiation stages in bone marrow are identified. From this point of view, cell surface antigens are specified. Thus, it is found that the myelotoxicity of a drug can be evaluated with a high efficiency at a high accuracy by using flow cytometry to analyze for a change in the quantity of bone marrow-derived cells expressing the cell surface antigens after administration of the drug to an animal.

Abstract: A multifunctional reagent for erythrocytes containing an amount sufficient to produce the lysis of erythrocytes or the sphering of erythrocytes in such a way that they can be detected by a cytometer or an automatic counting device, of a carbamate or of an agent inducing the formation by the erythrocytes, from carbonate and from a nitrogenated heterocycle or ammonium ions, of a carbamate combined with the absorption of CO2 by said erythrocytes, process for lysing or sphering erythrocytes and preparation process for leucocytes.

Abstract: An apparatus is provided for hematology testing, which has a sensing unit defining a counting orifice for the flow of a blood sample through the counting orifice to analyze the blood sample, and a pump unit having three syringes. A first syringe is coupled in fluid communication with the sensing unit on the inlet side of the counting orifice for injecting a stream of blood sample through the counting orifice. A second syringe is coupled in fluid communication with the sensing chamber on the inlet side of the counting orifice for simultaneously injecting a sheath of fluid surrounding the sample stream on the inlet side of the counting orifice. And a third syringe is coupled to the sensing chamber on the outlet side of the counting orifice for aspirating a sheath of fluid from the sensing chamber surrounding the sample stream on the outlet side of the counting orifice.

Abstract: A method of making a reference control containing a nucleated red blood cell component includes providing a blood cell containing a nucleus; treating the blood cell with a treatment solution to alter a nucleus property from a natural value to a target value suitable for simulating nucleated red blood cells on a blood analyzer; and suspending treated blood cell in a suspension medium to form a reference control. The method also includes integrating the nucleated red blood cell component with white blood cell, red blood cell, platelet and reticulocyte components. Further disclosed is a cell treatment composition for altering a nucleus property, which includes a conditioning component, a lytic component for permeating cell membrane, and a fixing component for preserving the cell nucleus. Also disclosed is a method of using the reference control for measurement of nucleated red blood cells on a blood analyzer.

Abstract: The invention provides a method for assaying for troponin I in a sample such as serum, the method comprising a determination of the troponin I concentration in a sample using a standard preparation that comprises a complete native troponin complex. One exemplary assay for troponin I concentration according to the invention is an immunoassay. Further contemplated in the method is a step comprising contacting the sample with a Ca2+-binding agent. Another aspect of the invention is the standard preparation comprising a complete native troponin complex. Yet another aspect of the invention is a kit for use in the assay method comprising the standard preparation, a detectable label, and a troponin I binding partner, such as an anti-troponin I antibody. All aspects of the invention are usefully practiced using human materials, such as a human troponin complex, and/or human sources for samples.

Abstract: The present invention relates to rapid methods for the detection of ischemic states and to kits for use in such methods. Provided for is a rapid method of testing for and quantifying ischemia based upon methods of detecting and quantifying the existence of an alteration of the serum protein albumin which occurs following an ischemic event; methods for detecting and quantifying this alteration include evaluating and quantifying the cobalt binding capacity of circulating albumin, analysis and measurement of the ability of serum albumin to bind exogenous cobalt, detection and measurement of the presence of endogenous copper in a purified albumin sample and use of an immunological assay specific to the altered form of serum albumin which occurs following an ischemic event.

Abstract: A diagnostic method and associated test kit for detecting an analyte residing in a test sample is provided. A sample membrane is utilized having a collection region and a detection region, the collection region having a known saturation volume for the intended test sample. A barrier is defined between the collection region and the detection region. The collection region is saturated with the test sample having a volume of less than about 100 microliters so that a known volume of the test sample is contained in the collection region. The barrier is removed from between the collection region and detection region of the membrane and a diluent is supplied to the collection region of the membrane to facilitate flow of the test sample from the collection region to the detection region of the membrane.

Abstract: A method of detecting parasite infection, particularly malaria, includes mixing a blood sample with a lytic reagent system to lyse red blood cells, and to form a sample mixture; performing a differential analysis of white blood cells of the sample mixture on a blood analyzer, and obtaining a cell volume distribution of a white blood cell subpopulation from a cell volume measurement used in the differential analysis; obtaining a cell volume parameter from the cell volume distribution of the white blood cell subpopulation; evaluating the cell volume parameter against a predetermined criterion, and reporting an indication of the parasite infection if the cell volume parameter meets the predetermined criterion. The method also uses a discriminant obtained from cell volume parameters of two different white blood cell subpopulations against a predetermined criterion. The method further use a cell distribution parameter of a cell distribution obtained using a RF impedance measurement.

Abstract: A reagent system is provided for substantially lysing red blood cells in a whole blood sample prior to leukocyte analysis, which system includes a first reagent for substantially lysing the red blood cells in the whole blood sample, and a second reagent for quenching the activity of the first reagent. The first reagent is formulated to include an autoclaved saponin compound and an acid selected from the group consisting of a halogenated carboxylic acid, a phosphoric acid and a combination thereof. The second reagent includes a base and has a pH value of about 8 to 12. Also provided is a method of lysing the red blood cells and stabilizing white blood cells present in a sample of whole blood.

Abstract: A cyanide-free lytic reagent composition and method of use for measuring the total hemoglobin concentration and white blood cells in a blood sample are disclosed. The lytic reagent composition includes a quaternary ammonium surfactant to lyse red blood cells and release hemoglobin and a ligand to form a stable chromogen with the hemoglobin. The lytic reagent composition has a pH in a range of 3 to 10. The lytic reagent composition can also include a second quaternary ammonium surfactant. The ligand can be malic acid, malonic acid, ethylene diamine, N,N-diethylethylene diamine, N,N?-diethylethylene diamine, diethylene triamine, tetraethylene pentamine, 1,6-hexanediamine, 1,3-pentanediamine, 2-methylpentamethylenediamine, 1,2-diaminocyclohexane, 4-aminoacetophenone, bis-hexamethylenetriamine, pyridazine, or 3,6-dihyroxypyridazine.

Abstract: A method of preparing a sample of muscle tissue and of assaying the prepared sample to determine the presence of prions in the sample is disclosed. The muscle tissue is homogenized and mixed with a complexing agent which forms a complex with a higher specific gravity than PrPSc, the complexing agent or other components of the homogenate. Gravity is then used (e.g. ultra centrifugation) to concentrate the complex and the concentrate is assayed to detect prions. The muscle tissue is preferably extracted from a muscle or group of muscles such as hind limb muscle which have a higher or more preferably the highest concentration of prions as compared to other muscle in the mammal.

Abstract: The invention provides compositions and methods for cell separation. These reagents and techniques specifically agglutinate cells via surface antigen recognition and can be used to recover even rare cell types in high yield.

Abstract: A sample is prepared from blood in a manner which makes it possible to further analyze proteins in the sample, e.g. to detect prions in the sample. Blood is extracted, allowed to clot and subjected to separation processing (e.g. centrifugation) to obtain serum. The serum is treated with a complexing agent which agent binds prions in the sample forming an agent/protein complex which makes it possible to concentrate the complex. Concentration of the complex results in a sample which can be successfully analyzed, e.g. assayed using a range of different types of assay methodologies for detecting prions.

Abstract: A method of making a reference control containing a nucleated red blood cell component includes providing a blood cell containing a nucleus; treating the blood cell with a treatment solution to alter a nucleus property from a natural value to a target value suitable for simulating nucleated red blood cells on a blood analyzer; and suspending treated blood cell in a suspension medium to form a reference control. The method also includes integrating the nucleated red blood cell component with white blood cell, red blood cell, platelet and reticulocyte components. Further disclosed is a cell treatment composition for altering a nucleus property, which includes a conditioning component, a lytic component for permeating cell membrane, and a fixing component for preserving the cell nucleus. Also disclosed is a method of using the reference control for measurement of nucleated red blood cells on a blood analyzer.

Abstract: A pretreatment kit and a pretreatment kit for saliva in identification and quantitative determination of mutans streptococci by immunochromatography utilizing an antigen-antibody reaction, which can remove aggregation caused by mucin and chain formation of mutans streptococci in saliva in a simple operation and can efficiently flow out a complex of a labeled antibody and mutans streptococci from a porous membrane retaining the labeled antibody, contains (A) a 0.01 to 10 mol/L aqueous solution of sodium hydroxide, (B) a 0.01 to 3 mol/L aqueous solution of tartaric acid and/or citric acid, and (C) a nonionic surface active agent and/or an amphoteric surface active agent, in which the component (C) is mixed with the components (A) and/or (B), or is provided separately, and at least one substance selected from the particular metallic salts is contained in at least one of the components (A), (B) and (C) in an amount of 5 to 25% by weight.

Abstract: The invention concerns a reagent for determination of leucocytes and measurement of haemoglobin in a sample of blood. This reagent comprises a buffer system that is suited to adjust selectively the pH of the reagent to an acidic value, at least one detergent of cationic type, a nitrogenous compound and, optionally, at least one inorganic salt. This reagent can be used in haematological analyses in human medicine and also permits the identification of a leucocytic subpopulation, in particular the basophil polymorphonuclear leucocytes.

Abstract: The invention describes quality control devices for assays that measure analytes in cells and tissue samples, and methods of use thereof. In particular, the quality control device comprises a matrix affixed with synthetic controls in different concentrations, or different synthetic controls. The quality control device can be adhered to a microscope slide via an adhesive or chemically attached to a microscope slide and processed simultaneously with a tissue sample.

Abstract: An improved reagent system for preparation of cells for flow cytometry having a physiologically compatible salt solution composition including a lysing agent, an agent for minimizing white blood cell lysis, and optionally a preservative.

Abstract: A method for processing blood samples in order to produce DNA complex patterns for diagnostic applications.

Abstract: A method for measuring immature granulocytes in a blood sample is described. The method includes the steps of lysing red blood cells of a blood sample with a lytic reagent, analyzing the sample mixture by DC impedance measurement, determining immature granulocytes from obtained DC histogram, and reporting immature granulocytes in the blood sample. The method further includes measuring nucleated red blood cells in the blood sample.

Abstract: A method for discriminating and counting erythroblasts comprises the steps of: (i) staining leukocytes in a hematologic sample by adding a fluorescent labeled antibody capable of binding specifically with leukocytes to the hematologic sample; (ii) raising the permeability only of cell membranes of erythroblasts in the hematologic sample to a nucleotide fluorescent dye which does not permeate a cell membrane usually, the nucleotide fluorescent dye having a fluorescent spectrum capable of being distinguished from that of a fluorescent labeling compound of the fluorescent labeled antibody in step (i); (iii) staining nuclei of the erythroblasts in the hematologic sample with the nucleotide fluorescent dye; (iv) subjecting the hematologic sample to flowcytometry to detect at least two fluorescent signals from each cell; and (v) discriminating and counting the erythroblasts from difference in intensity between the at least two fluorescent signals.

Abstract: A method for classifying and counting leukocytes comprises the steps of: (1) adding to a hematological sample the following fluorescence-labeled antibodies labeled with fluorescent dyes which emit fluorescences distinguishable from each other; (a) a first fluorescence-labeled antibody (1st antibody) which bonds specifically to leukocytes, (b) a second fluorescence-labeled antibody (2nd antibody) which bonds to at least one kind of neutrophilic cells, and (c) a third fluorescence-labeled antibody (3rd antibody) which bonds to at least one kind of immature granulocytic cells, in order to stain leukocytic cells in the sample, and removing erythrocytes from the sample; (2) analyzing the resulting sample using a flow cytometer to measure at least one scattered light signal and three separate fluorescence signals; (3) defining a group of granulocytic cells on the basis of intensity of the scattered light and intensity of fluorescence from the 1st antibody; (4) defining neutrophilic cells in the defined group of gra

Abstract: An improved fecal occult blood test having a matrix such as paper that is treated, imprinted or impregnated with a test reagent capable of undergoing a chromogen reaction is disclosed. The improvement relates to a novel developing solution in which the water to alcohol ratio is adjusted to enhance the sensitivity of the test.

Abstract: A lytic reagent composition and the method of use for differential analysis of leukocytes using flow cytometry are disclosed. The lytic reagent composition includes a short chain alkyl oxyethanol, such as 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, or 2-isopropoxyethanol, in a sufficient amount to preserve leukocytes; a non-lysing nonionic surfactant as a debris solublizer; and an inorganic buffer to maintain pH of the lytic reagent composition in a range from 9.1 to 10.7. The lytic reagent composition is used to lyse red blood cells and preserve leukocytes, as well as used as the sheath reagent for the focus flow measurement. The lytic reagent composition, when used on a flow cytometric analyzer with multiple angle light scatter and light absorbance measurements, enables differentiation of leukocytes into five subpopulations.

Abstract: Automated staining equipment that can mix reagents is used to spray a Romanowsky stain onto slide mounted specimens which are then briefly centrifuged. The centrifugation step removes excess stain leaving only a thin film. Depending on the time of the centrifugation step, most of the organic solvent and part of the water in the stain are evaporated by airflow through the equipment. This greatly accelerates the staining reaction and preserves water soluble structures such as the granules in basophilic leukocytes. For optimal performance, this staining procedure requires a thiazin-eosin stain with about 90% to about 40% organic solvent, such as methanol, and only about 10% to about 60% water. This is a unique staining reagent in Romanowsky staining.

Abstract: The present invention provides reagents for use in an automated environment for cell conditioning of biological samples wherein the cells or tissues are predisposed for access by reagent molecules for histochemical and cytochemical staining procedures. The components of the reagents are optimized to facilitate molecular access to cells and cell constituents within the biological sample. The present invention also provides reagents for use in an automated environment for removing or etching embedding media by exposing a biological sample to be stained in histochemical or cytochemical procedures without the dependence on organic solvents. The components of the reagents are optimized to facilitate removal or etching of the embedding media from the biological sample.

Abstract: Instruments and processes according to the invention provide for the preparation of a fluid sample that has a substantially known concentration of a select particulate matter. In one aspect, the invention is understood as laboratory instruments for sample preparation. These instruments can include a filter that is submersible within a fluid suspension of particulate matter. To collect particulate matter from the fluid suspension, the instruments can cause a fluid flow that pulls fluid across the filter to trap particulate matter against one surface of the filter. The instruments can then remove the filter from the fluid suspension and dispose the filter above a collection vessel such that the side of the filter that is carrying particulate matter is positioned above the opening of the collection vessel.

Abstract: An apparatus is provided for hematology testing, which has a sensing unit defining a counting orifice for the flow of a blood sample through the counting orifice to analyze the blood sample, and a pump unit having three syringes. A first syringe is coupled in fluid communication with the sensing unit on the inlet side of the counting orifice for injecting a stream of blood sample through the counting orifice. A second syringe is coupled in fluid communication with the sensing chamber on the inlet side of the counting orifice for simultaneously injecting a sheath of fluid surrounding the sample stream on the inlet side of the counting orifice. And a third syringe is coupled to the sensing chamber on the outlet side of the counting orifice for aspirating a sheath of fluid from the sensing chamber surrounding the sample stream on the outlet side of the counting orifice.

Abstract: A method for the preparation of a stable autologous or homologous coagulant from whole blood is disclosed. The direct precipitation of anticoagulated whole blood obviates the need for a plasma isolation step with unexpected results. The autologous or homologous coagulant produced by the method of the present invention demonstrated clotting times equivalent to commercially available bovine thrombin and human thrombin preparations, with improved kinetics of growth factor release from activated platelets over preparations of bovine thrombin.

Abstract: A lytic reagent composition and the method of use for differential analysis of leukocytes using flow cytometry are disclosed. The lytic reagent composition includes a short chain alkyl oxyethanol, such as 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, or 2-isopropoxyethanol, in a sufficient amount to preserve leukocytes; a non-lysing nonionic surfactant as a debris solublizer; and an inorganic buffer to maintain pH of the lytic reagent composition in a range from 9.1 to 10.7. The lytic reagent composition is used to lyse red blood cells and preserve leukocytes, as well as used as the sheath reagent for the focus flow measurement. The lytic reagent composition, when used on a flow cytometric analyzer with multiple angle light scatter and light absorbance measurements, enables differentiation of leukocytes into five subpopulations.

Abstract: An improved reagent system for preparation of cells for flow cytometry having a physiologically compatible salt solution composition including a lysing agent, an agent for minimizing white blood cell lysis, and optionally a preservative.

Abstract: Methods and compositions are provided for gently lysing and solubilizing cells. Methods and compositions are further provided for quickly purifying high quality low molecular weight nucleic acid from host cells. Target cells are treated with a pre-chilled lysis solution having a zwitterionic detergent, for example n-Dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate, and a brief room-temperature incubation. Where nucleic acid purification is required, the lysis solution-treated cells are contacted with a nucleic acid capture matrix having an average pore size of at least about 1 &mgr;m.

Abstract: The present invention provides a method for preparing cells for use in a hematology blood control. The preparation steps, namely the use of cross-linking agents such as aldehydes, involve a step-wise process starting with very low concentrations of a cross-linking agent. Successive fixations involve an increase in the concentration of cross-linking agent.

Abstract: A control composition, and method of preparing a control composition, that includes stabilized, mammalian granulocytes having altered physical properties so that the granulocytes function as a human lymphocyte analogs when used on an automated blood cell analyzer.

Abstract: Cyanide-free reagents for the determination of hemoglobin and leukocytes present in a blood sample comprise an aqueous solutions of at least one quaternary ammonium salt, preferably selected from the group of alkyltrimethylammonium salts, alkyldimethylbenzylammonium salts or alkylpyridium salts consisting of tetradecyltrimethyl ammonium bromide (TTAB), dodecyltrimethyl ammonium chloride, cetyltrimethyl ammonium bromide, hexadecyltrimethyl ammonium bromide and benzalkonium chlorides, and hydroxylamine salts, especially hydrochloride, sulfate and phosphates and other acid salts. The method involves mixing the reagent with a diluent-diluted blood sample, presenting it to an absorbance spectrophotometer and measuring the resulting optical density as an indicator of hemoglobin concentration. This cyanide-free reagent could be used solely for hemoglobin determinations, or, it can also be used in leukocyte counting and sizing using hematology instrumentation.

Abstract: The present invention provides systems, methods, and screens for an optical system analysis of cells to rapidly determine the distribution, environment, or activity of fluorescently labeled reporter molecules in cells for the purpose of screening large numbers of compounds for those that specifically affect particular biological functions. The invention involves providing cells containing fluorescent reporter molecules in an array of locations and scanning numerous cells in each location with a high magnification fluorescence optical system, converting the optical information into digital data, and utilizing the digital data to determine the distribution, environment or activity of the fluorescently labeled reporter molecules in the cells. The array of locations may be an industry standard 96 well or 384 well microtiter plate or a microplate which is microplate having cells in a micropaterned array of locations.

Abstract: An improved control for a hematology analyzer. In one embodiment, blood cells are treated for permitting the cells to simulate nucleated red blood cells for detection or analysis by the hematology analyzer.

Abstract: The first subject of this invention is a column packing material comprising:

Abstract: Automated staining equipment that can mix reagents is used to spray a Romanowsky stain onto slide mounted specimens which are then briefly centrifuged. The centrifugation step removes excess stain leaving only a thin film. Depending on the time of the centrifugation step, most of the organic solvent and part of the water in the stain are evaporated by airflow through the equipment. This greatly accelerates the staining reaction and preserves water soluble structures such as the granules in basophilic leukocytes. For optimal performance, this staining procedure requires a thiazin-eosin stain with about 90% to about 40% organic solvent, such as methanol, and only about 10% to about 60% water. This is a unique staining reagent in Romanowsky staining.

Abstract: The present invention provides reagents for use in an automated environment for cell conditioning of biological samples wherein the cells or tissues are predisposed for access by reagent molecules for histochemical and cytochemical staining procedures. The reagents comprise components optimized to facilitate molecular access to cells and cell constituents within the biological sample. The present invention also provides reagents for use in an automated environment for removing or etching embedding media by exposing a biological sample to be stained in histochemical or cytochemical procedures without the dependence on organic solvents. The reagents comprise components optimized to facilitate removal or etching of the embedding media from the biological sample.

Abstract: An Agent for the removal of turbidity and biological samples including 0.5-10 mM Phenol, 0.5-15% polyoxyethylated triglyceride and at least one non-ionic tenside in a range of 0.5-15% capable of dissolving the polyoxyethylated triglyceride.

Abstract: A method for differentiating and enumerating nucleated red blood cells in a blood sample is described. The method includes the steps of lysing red blood cells of a blood sample with a lytic reagent, measuring nucleated blood cells by DC impedance measurement in a non-focused flow aperture, differentiating nucleated red blood cells from other cell types, and reporting nucleated red blood cells in the blood sample. The method further includes subtracting nucleated red blood cells and other interference materials from the count of remaining blood cells, and reporting a corrected white blood cell count of the blood sample. Additionally, the method further includes measuring spectrophotometric absorbance of the sample mixture at a predetermined wavelength of a hemoglobin chromogen formed upon lysing the blood sample, and reporting hemoglobin concentration of the blood sample.

Abstract: A method for differentiating and enumerating nucleated red blood cells in a blood sample is described. The method includes the steps of lysing red blood cells of a blood sample with a lytic reagent, measuring nucleated blood cells by DC impedance measurement in a non-focused flow aperture, differentiating nucleated red blood cells from other cell types, and reporting nucleated red blood cells in the blood sample. The method further includes subtracting nucleated red blood cells and other interference materials from the count of remaining blood cells, and reporting a corrected white blood cell count of the blood sample. Additionally, the method further includes measuring spectrophotometric absorbance of the sample mixture at a predetermined wavelength of a hemoglobin chromogen formed upon lysing the blood sample, and reporting hemoglobin concentration of the blood sample.

Abstract: A leukocyte accumulation container having an opening, a sidewall portion and a bottom portion, part or all of the sidewall portion having a horizontal section area gradually increasing in a direction from the bottom portion towards the opening. A cytolytic agent is added to a solution of a platelet preparation or a solution of an erythrocyte preparation to solubilize platelets or erythrocytes in the solution of the preparation. The leukocyte accumulation container then is set on a centrifuge to accumulate the leukocytes on the bottom portion of the leukocyte accumulation container, and the leukocytes accumulated on the bottom portion are counted.

Abstract: Reagents and a method for simple and rapid discrimination and counting of erythroblasts in peripheral blood or circulatory system-related samples accurately with high precision is disclosed. The reagents include a hemolytic agent for dissolving erythrocytes in a body fluid sample and for conditioning leukocytes and erythroblasts in the sample to be suitable for staining, and including at least one fluorescent dye selected to stain leukocytes and erythroblasts differentially. When the selected fluorescent dye is mixed with the sample, a detectable difference in fluorescence intensity at least between leukocytes and erythroblasts arises under laser illumination in flow cytometric analysis. The reagents further include surfactant added to the hemolytic agent, selected to enable flow cytometric discrimination of erythroblasts in the body fluid sample by their maturation stages.