Sysmex Journal International

2001Vol.11 No.1


Performance Evaluation of Two Haematology Analysers: the Sysmex KX-21 and the Beckman Coulter Ac.T diff


Ahmed Khaled FARES

Haematology Department of Princess Iman Research and Laboratory Sciences Centre


The purpose of this study was to evaluate the automated haematology analyser KX-21 manufactured by Sysmex Corporation, Japan and the haematology analyser Coulter AC.T diff manufactured by Beckman Coulter Corporation, USA and to recommend the suitable one for armed forces hospitals and health centres in Jordan.

The evaluation included precision, linearity, and carryover, which were tested and compared to manufacturers’ claimed levels. The correlation studies were carried out on a significant number of normal and abnormal specimens against results from Sysmex K-1000 and Sysmex SE-9000.

Precision: Coefficient of variation ( CV ) for each complete blood count ( CBC ) parameter and the three part differential count as measured by the KX-21 indicated acceptable performance whereas only the lymphocyte ( LYMPH ), monocyte ( MONO ), granulocyte ( GRAN ) parameters of AC.T diff were within specifications.

Linearity: Linearity for all dilution sensitive parameters, white blood cell ( WBC ), red blood cell ( RBC ), hemoglobin ( HGB ), and platelets ( PLT ), on both analysers was acceptable.

Carryover: Carryover for total WBC, RBC, HGB, HCT, and PLT were within the manufacturers’ specifications for the KX-21. The only result that exceeded the upper limit of acceptability was the PLT carryover on the AC.T diff whereas the WBC, RBC, HGB, and hematocrit ( HCT ) were within the manufacturer’s specifications.

Correlation coefficient: Correlation coefficient ( r ) values for most parameters were greater than 0.95 for the two analysers. However, there were areas in which their performance was less than optimal.

It was found that in addition to the scientific assessment carried out in this study, other important factors for full evaluation would make Sysmex KX-21 relatively superior. Those factors should be considered and followed as described by International Council for Standardization in Haematology ( ICSH ) and National Committee for Clinical Laboratory Standards ( NCCLS ) protocols.


Automated Hematology Analyzer, KX-21, Coulter, AC.T diff, Performance