Abstract: A cytoanalyzer includes a flow cell for aligning cells and permitting the same to pass therethrough, a semiconductor light emitting device for emitting a laser beam to the cells passing through the flow cell, and a light-detecting device having at least two separate photosensing portions capable of sensing two types of light scattered by each of the cells. The alignment of the cytoanalyzer may be achieved by comparing intensities of light on the at least two separate photosensing portions.

Abstract: A method for classifying and counting leukocytes which includes the steps of (i) adding a first reagent used for classifying leukocytes into four groups which contains, (a) at least one ionic surfactant in a sufficient amount to lyse erythrocytes and to damage a part of cell membrane of leukocytes, (b) at least one organic compound having an anionic group in a sufficient amount to bond with a cationic component present in leukocytes to give morphological differences between leukocytes, (c) a nonionic surfactant, and (d) a buffer for adjusting pH, to a part of a blood sample to determine information on the cell size and morphological features in order to classify leukocytes into four groups consisting of three groups corresponding to lymphocytes, mononuclear cells and eosinophils and one group corresponding to neutrophils and basophils; (ii) adding a second reagent used for measuring basophils to another part of the blood sample to determine information on at least the cell size in order to classify basophils,

Abstract: A reagent for analyzing leukocytes having at least one nonionic surfactant having an addition polymerization molar number of polyoxyethylene of 3 to 9, at least one cationic surfactant, and a buffer adjusting a pH value to 2.5 to 4.0, which can determine a cell size of and the morphological features of leukocytes contained in the blood sample.

Abstract: A particle analyzer includes a flow cell for enclosing an electrolyte flow containing particles in a sheathed flow, the flow cell including a first and second cells which are interconnected through an orifice, the sheathed flow flowing through the orifice from the first cell to the second cell, a first and second electrodes provided in the first and second cells, respectively and a voltage application device for applying voltage between the first and second electrodes. The particle analyzer further includes a resistance detection device for detecting a variation of electric resistance between the first and second electrodes when the particle passes through the orifice to output the detected variation as a resistance detection signal. A first diameter calculation device is included for calculating each diameter of the particles based on the detected variation of electric resistance.