Abstract: 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.

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: An agent for determining ristocetin cofactor (v.Willebrand factor) is described, which contains platelets which have been treated with a tanning agent, with a protease inhibitor and, optionally, with a dye-stuff, and ristocetin A.

Abstract: An improved multi-purpose blood diluent is provided which is isotonic, with a neutral pH for avoiding cell volume change. The diluent of the invention provides balance between the effects on cell volume of a preservative for the solution, and the effects of a surfactant. The diluent of the invention is particularly useful as a carrier for blood samples in instruments which automatically provide medical diagnostic determinations of blood samples. The diluent herein includes conventional sodium and potassium chlorides as electrolytes, pH buffers, such as monobasic and dibasic phosphate, and ethylene diamine tetraacetic acid to control and chelate the divalent cations. The balanced preservative-surfactant combination may include, for example, 2-phenoxyethanol with certain ethylene oxide-polypropylene glycol condensation products.

Abstract: Hematologic control and calibration standards are disclosed which are essentially plasma-free. These controls are prepared by the suspension of red blood cells in an appropriate buffer containing a stabilization effective amount of disaccharides, and other optional ingredients. Control and calibration standards prepared in the foregoing manner are suitable in the control and calibration of hematology analyzers for the following parameters: white cell count, red cell count, hemoglobin, hematocrit and the common derived parameters (i.e., mean cell volume, mean cell hemoglobin and mean cell hemoglobin concentration). The addition of platelets to the foregoing suspensions is also contemplated to provide a control for platelet parameters.

Abstract: 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.

Abstract: A lysable, blood platelet reference control comprising a suspension of a mixture of permanently shrunken animal red blood cells in a suspension medium non-deleterious to said cells, said cells having been partially fixed with a fixing agent to reduce cell membrane elasticity prior to being shrunken, and said mixture of permanently shrunken cells in said suspension medium simulating in number, size and volume distribution the platelets present in human whole blood.

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

Abstract: This invention utilizes for stabilization of platelets a combination of iodoacetamide and an iminodiacetic acid or salt thereof, together with a compatible bacteriostatic agent, in an aqueous electrolytic solution which is maintained at a preselected range of pH and osmolality.In a preferred formulation, the stabilizing solution contains iodoacetamide, N-(2-acetamido)iminodiacetic acid and sodium penicillin. Ethylenediaminetetraacetic acid, or salts thereof, are optionally present as an additional ingredient.

Abstract: Biological cell compositions are stabilized to preserve aldehyde functionality by formation of acetal, particularly cyclic acetal, primarily in order to prevent cell-to-cell crosslinking. The stabilized biological cells are particularly useful as human blood particle analogs in reference reagents employed in electronic hematology testing instrumentation.A process for preparing the acetal-stabilized biological cells employs reaction of polyaldehyde-treated biological cells with alcohol, preferably including 1,2 dialcohol, under acidic conditions; thereafter, the resulting product solution is adjusted to basic condition, stabilizing the acetal formation on the biological cells.

Abstract: Stabilized reference control and calibrator compositions for determining multiple platelet parameters in stand alone platelet controls and whole blood reference controls are prepared from platelets stabilized with a fixative-stabilizing composition containing glutaraldehyde and a non-ionic surfactant which is a mixture of ethoxylates of certain isomeric linear alcohols.