Coulter Electronics, Inc.

Coulter Corporation

Stephen L Ledis

Harold R Crews

James H Carter

Ted Sena

David L Chastain, Jr

Timothy J Fischer

Carlos M Rodriguez

Dave Chastain, Jr

Robert Cary Leif

Fred L Larsen

Robert I Feinberg

A lytic reagent composition and a kit of a lytic reagent system are disclosed for the rapid isolation, identification and/or analysis of at least five subpopulations of leukocytes from a whole blood sample. The composition and system have 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. The lytic reagent composition of this invention comprises saponin and a carboxylic acid of the formula RCOOH wherein R is H or a C.sub.1-3 aliphatic hydrocarbon radial optionally substituted by one or more carbonyl and/or hydroxy groups. The kit of a lytic reagent system comprises the lytic reagent composition and a quench reagent.

Method and reagent system for isolation, identification and/or analysis

A reticulocyte analyzing method and apparatus in which a biological sample stream of ghosted red cells is passed into and through a point focused beam of light, such as laser light. A light detector structure is positioned with respect to the axis of the light beam to provide a light output pulse indicative of the passage of each cell. Electrically conductive contacts within the fluid stream can provide additional electrical pulse outputs of each cell. A staining reagent can be utilized with a ghosting reagent to further differentiate the reticulocytes. The light and the light and electronic produced output pulses or signals can be combined to define and quantify reticulocytes as distinct from other known cell types.

Reticulocyte analyzing method and apparatus utilizing light scatter

Specified classes and subclasses of leukocyte blood cells are identified by immunohematology procedures, based on utilization of antigenic determinants on the cell surface, their reactivity with antibodies which fluoresce under known circumstances, and identified by utilization of principles of flow cytometry or morphology. This invention particularly concerns improvements in the lysing and fixing method used prior to detection and identifying of the cells. In this method, a whole blood sample first is incubated with a reagent including antibodies to the cell subclass to be identified, the antibodies having directly or indirectly made fluorescently responsive to a particular light (e.g. argon ion laser). The red blood cells then are lysed with a reagent containing saponin. Next follows a leukocyte fixing treatment, preferably using a cross-linking dialdehyde composition, such as glyoxal or glutaraldehyde. Details are given as to time, temperature, concentration, and the use of additives and stains, as well as the use of particular monoclonal antibodies in the preferred procedure.

Reagent system and method for identification, enumeration and

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. The advantage and uniqueness of this reagent system is the surprising speed at which it is able to effect the foregoing objectives (generally less than 10 seconds at room temperature) and the ability to further differentiate the leukocyte population (notably, the granulocyte population). Following stromatolysis, a quenching agent is added to retard the reactivity of the lytic reagent system and, thus, inhibit any further dramatic changes to the leukocyte population. The treatment of the whole blood sample in the foregoing manner is further unique in that the leukocyte fraction of the sample has retained its characteristic immunochemical response.

Lysing reagent system for isolation, identification and/or analysis of

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.

Multi-purpose blood diluent and lysing agent for differential

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.

Method and reagents for differential determination of four populations

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.

A method and reagent system is described for differential determination of three-populations of leukocytes (lymphocyte, monocyte and granulocyte), using an automatic counting system. The reagent system includes a blood diluent and lysing reagent. The blood diluent is an osmotically balanced aqueous solution of ingredients at a preselected pH for maintaining erythrocyte morphology, blood cell stabilizing, buffering and bacteriostatic action. The lysing reagent is a mixture of an aqueous solution of quaternary ammonium salts, which lysing reagent is added to the diluted blood under more mild conditions of concentration and at a slower rate than is current practice in order to obtain an unexpected volumetric modification of at least one of the three-populations of leukocytes, whereby volumetric differential analysis can be accomplished.

Method for three-volume differential determination of lymphocyte,

A process for preparing whole blood reference controls having long term stability up to six months for devices using electronic means for whole blood determinations including platelet count and mean cell volume and red blood distribution width. The preconditioning diluent for the red blood cells consists essentially of an aqueous solution of lactose, sodium azide, and a non-ionic surfactant and is pH buffered and osmolality adjusted. The media of the whole blood control includes lactose, fungicides and antibiotics, and supplementary agents including purine nucleosides. It also includes additional components which alter red blood cell membranes including bile salts and cholic acid derivatives, phenothiazine compounds and the salts thereof having antihistamine properties, and 4-aminobenzoic acid ester derivatives and their salts having local anesthetic properties. In the process, the red blood cells are separated from the whole blood and preconditioned by the diluent to attain desired size distribution width and volume. The preconditioned red blood cells then are mixed in the media in suitable number for yielding the desired cell count for the whole blood reference control.

Process for preparing whole blood reference controls having long term

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, dimethylolurea and chlorhexidene diacetate 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.

This invention relates to a lytic diluent and a method for rapid lysing of red blood cells in whole blood for a differential determination of lymphoid and myeloid populations of leukocytes, and measurement of hemoglobin, particularly for use in automatic particle counting systems. The diluent is a mixture of at least one quaternary ammonium salt having surface active properties, and an additive in suitable proportions, buffered to an acid pH of 3.5 to 5.0. The additive includes 2-phenoxyethanol and other short chain alkanols substituted by one phenyl or phenoxy, as well as certain polyhydroxy compounds. When the reagent is employed in lower concentrations, an alkaline reagent comprising a quaternary ammonium salt and an alkali metal cyanide, buffered to an alkaline pH, may be added to complete the chromagen formation.

Differential lymphoid-myeloid determination of leukocytes in whole blood

A method is described for preparing a human platelet analog for use as a reference control in particle analysis instrumentation of the Coulter type. Goat erythrocytes from individual goats which have been selected with respect to age, sex, selective breeding, a controlled environment, prior veterinary treatment, and diet are altered in size and/or combined with samples from several goats, as needed, to obtain a blend for use as a reference control for automated particle counting equipment in which the goat erythrocytes simulate in number, size and distribution the platelets in human whole blood. The controls are useful as a free-standing reference for determination of human platelets only, or can be added to whole blood reference controls for multi-parameter instruments.

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Hialeah, FL, United States of America

Stephen L Ledis