Sysmex Journal International

2000Vol.10 No.1


Evaluation of the Differential Leukocyte Count and Screening Efficiency of the Sysmex SE-9000 Haematology Analyser


Ahmed KHALED FARES, Bassma HAKOOZ, and Shubeilat TAISIR

Haematology Department of King Hussein Medical Centre


The purpose of this study was to evaluate the white blood cell ( WBC ) differential count and screening efficiency of the Sysmex SE9000 haematology analyser compared to the visual 400-cell WBC differential count according to the NCCLS H20-A protocol. Automated WBC differential counts were performed on 756 samples during the first 10 days of use of the analyser in the Department of Haematology at King Hussein Medical Centre.

Reference WBC differential counts were performed by microscopy examination of 400 WBC cell counts on May-Grünwald-Giemsa stained blood films.

Automated WBC differential counts were considered positive if they contained a WBC flag indicating the presence of abnormal cells. The automated WBC differential counts were then classified as true positive ( TP ), false positive ( FP ), true negative ( TN ), and false negative ( FN ).

Correlations were excellent with the exception of basophils: for neutrophils r = 0.99, for lymphocytes 0.98, monocytes 0.81, eosinophils 0.95, and basophils 0.74. Sensitivities for morphologic and distributional abnormalities were 68.4 % and 98 %, respectively.

Our evaluation demonstrated excellent performance of the SE-9000 with reference to the automated WBC differential count. The screening efficiency of the SE-9000 was very high, significantly reducing the manual workload. On the other hand, analysis of qualitative flags underscored the continuing importance of the blood film examination.


Automated Hematology Analyzer, SE-9000, Differential, Accuracy, Sensitivity, Specificity, Efficiency