CelQuant 5 adopts highly stable, long lasting and economical semi conductor laser light source. Multi angle laser scattering to accurately test cell size, cell nucleus, cell content granulars and complexity information, combined with cytochemical staining technique to conduct differential WBCs. At the same time screening out the abnormal cells, thus increasing the efficacy for abnormal samples. After the effect of reagent, the WBC sample is pipetted into diluent filled flow unit. Under the package of sheath liquid which is formed by diluent, every single cell passes through the center of flow unit.