Patent ID: 6900023

Claim:
A method for classifying and counting leukocytes comprising 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 which binds specifically to leukocytes, (b) a second fluorescence-labeled antibody which binds to at least one kind of neutrophilic cells, and (c) a third fluorescence-labeled antibody which binds to at least one kind of immature granulocytic cells, in order to stain the leucocytic cells in the hematological sample; (2) removing erythrocytes from the hematological sample; (3) analyzing the resulting hematological sample using a flow cytometer to measure at least one scattered light signal and three separate fluorescence signals; (4) classifying granulocytic cells on the basis of intensity of the scattered light and intensity of fluorescence from the first fluorescence-labeled antibody; (5) distinguishing eosinophils and neutrophilic cells in the granulocytic cells obtained in step (4) on the basis of the intensity of the fluorescence from the first fluorescence-labeled antibody and the intensity of the fluorescence from the second or third fluorescence-labeled antibody; (6) classifying the neutrophilic cells obtained in step (5) into groups different in degree of maturity on the basis of the intensity of the fluorescence from the second fluorescence-labeled antibody and the intensity of the fluorescence from the third fluorescence-labeled antibody; and (7) counting the number of cells in each of the groups.