Abstract: A reagent for partially lysing a cell membrane of a red blood cell infected with a malaria parasite, comprising: a first surfactant which has predetermined lysing ability for the red blood cell membrane; and a second surfactant which has weaker lysing ability than that of the first surfactant; wherein the reagent has pH of 5 to 7 and osmotic pressure of 200 to 300 mOsm/kg·H2O; and wherein the reagent partially lyses the malaria infected red blood cell membrane such that a malaria parasite is retained in the red blood cell and fluorescent dye passes through the cell membrane, is disclosed. A reagent for detecting malaria infected red blood cells, and a sample analyzing method for detecting malaria infected red blood cells, are also disclosed.

Abstract: The present invention is to present a blood analyzer which can prevent an abnormal number of white blood cells caused by the lipid particles or the red blood cells of poor hemolysis from being output. The blood analyzer comprises: first white blood cell number obtaining means; second white blood cell number obtaining means; output means for outputting the number of the white blood cells obtained by the second white blood cell number obtaining means, and determining means for determining whether the number of the white blood cells obtained by the second white blood cell number obtaining means is abnormal, wherein the output means is configured to output the number of the white blood cells obtained by the first white blood cell number obtaining means when the determining means determines that the number of the white blood cells obtained by the second white blood cell number obtaining means is abnormal.

Abstract: A blood analyzing method is described that includes steps of: preparing a measurement sample by hemolyzing red blood cells in a blood specimen, the measurement sample containing particles; irradiating a light on the measurement sample to detect two or more types of optical information reflecting characters of the particles in the measurement sample, thereby acquiring data indicating light intensities of the respective optical information as a particle data associated with each of the particles; counting white blood cells based on the particle data; outputting the result of counting white blood cells; determining whether malarial parasites are present or not based on the particle data; and outputting the result of determining. A blood analyzer also described.

Abstract: A reagent for partially lysing a cell membrane of a red blood cell infected with a malaria parasite, comprising: a first surfactant which has predetermined lysing ability for the red blood cell membrane; and a second surfactant which has weaker lysing ability than that of the first surfactant; wherein the reagent has pH of 5 to 7 and osmotic pressure of 200 to 300 mOsm/kg·H2O; and wherein the reagent partially lyses the malaria infected red blood cell membrane such that a malaria parasite is retained in the red blood cell and fluorescent dye passes through the cell membrane, is disclosed. A reagent for detecting malaria infected red blood cells, and a sample analyzing method for detecting malaria infected red blood cells, are also disclosed.

Abstract: Aqueous blood-sample diluting reagent and method of its use for compelling a morphological change in a blood sample to yield an MCV value assayed at elapsed time after the sample is drawn to be consistent within a diagnostically acceptable range with the original, immediate post-drawing MCV value. Selection of a small amount of a predetermined surfactant added within a limited range of concentration, and of a salt for adjusting osmotic pressure of the sample is thereby determined. The blood sample is treated with an anti-coagulant agent immediately post-drawing, and for assay in a particle analyzer at post-drawing elapsed time is diluted with the reagent solution. The reagent has an osmotic pressure (&pgr;) of approximately 150-400 mOsm/kg and a pH of 6.0-8.5. The surfactant is present in a 0.0005% to 0.5% concentration and has a hydrophile-lipophile balance (HLB) of 10-20.

Abstract: A reagent for measurement of leukocytes and hemoglobin concentration in the blood includes a cationic surfactant in an amount sufficient to lyse erythrocytes and denature hemoglobin, at least one of the following hemoglobin stabilizers:(a) sulfosalicylic acid, or its salt, in an amount effective for promoting the conversion of hemoglobin into methemoglobin,(b) 0.2 to 10.0 g/L of a water-soluble chelating agent having a nitrogen atom and a carboxyl group, and(c) piperazine, or its salt, in an amount effective for promoting the conversion of hemoglobin into methemoglobin, anda buffer for maintaining pH at 4 to 6.

Abstract: A reagent for analyzing leucocytes comprises (a) at least one ionic surfactant, being either a cationic or an amphoteric surfactant, in an amount sufficient for lysing erythrocytes and causing damage to a part of cell membranes of leucocytes; (b) at least one organic compound having a hydrophobic group and an acidic group which has a negative charge in an aqueous solution in an amount sufficient for a preserving leucocyte morphology by combining with a cationic component in leucocytes; (c) a nonionic surfactant; and (d) a buffer for adjusting pH.

Abstract: A reagent for measurement of leukocytes and hemoglobin concentration in the blood includes a cationic surfactant in an amount sufficient to lyse erythrocytes and denature hemoglobin, at least one of the following hemoglobin stabilizers: (a) sulfosalicylic acid, or its salt, in an amount effective for promoting the conversion of hemoglobin into methemoglobin, (b) 0.2 to 10.0 g/L of a water-soluble chelating agent having a nitrogen atom and a carboxyl group, and (c) piperazine, or its salt, in an amount effective for promoting the conversion of hemoglobin into methemoglobin, and a buffer for maintaining pH at 4 to 6.