Patent ID: 7354727

Claim:
A method for classifying B-lymphocytes, comprising the steps of: (1) preparing a measurement sample by mixing a blood sample with a lysing reagent to lyse erythrocytes and maintaining a mixture of said lysing reagent and said blood sample for from 15 to 60 minutes to shrink B-lymphocytes in said blood sample; (2) flowing said measurement sample through a flow cell of a flow cytometer; (3) radiating a light beam onto each individual cell in the measurement sample that is flowing through the flow cell; (4) detecting at least two scattered light emitted from the irradiated cells, wherein said two scattered light are selected from the group consisting of forward scattered light, backward scattered light, and side scattered light; (5) preparing a two-dimensional scattergram using the detected two scattered light by plotting intensities of the detected two scattered light from each of the cells; (6) specifying a region of a B-lymphocyte cluster on the two-dimensional scattergram using the detected two scattered light; and (7) counting the number of B-lymphocytes in the specified region.