[Developments of automated cell counter and its clinical laboratory application]

A rapid development has taken place in recent years in the field of automatic cell counting and automatic differential machine for miscellaneous blood cells. In the present paper we concisely summarized the history on the development of these machines, then reported the results obtained using STKS-VCS (automatic blood cell counter and cell analyzer based on flow system). 1. The precision of the STKS was established as follows using the coefficient of variation, 0.39-3.96% for 5 CBC parameters. WBC differentials; under 1% for neutrophils and lymphocytes, 6 to 9% for monocytes and eosinophils, approximately 18% for basophils. 2. Time profile of CBC and WBC differential data by same machine, was almost unchanged until 24 hours from blood taking using both glass and plastic vials. 3. Good correlation was obtained as for white cell differential between data from VCS and by manual ones with 4 skilled technicians according to NCCLS method. 4. Predictive value of tests applied to normal and abnormal population, high true positive and negative ratio and low false positive and negative ratio, which results helped us, to share more times to observe abnormal samples more carefully. 5. So called "flags" which predicts presence of abnormal cells (e.g. immature granulocytes, atypical lymphocytes) was useful to screen abnormal cell population in VCS system.