Evaluation of the Toa E-5000 Automated Hematology Analyzer

A three-phase evaluation of the Toa E-5000 Automated Hematology Analyzer was performed. The first phase consisted of evaluation of linearity, carryover, precisions, accuracy, sample stability, and effectiveness of the mixing and sampling mechanism. The second phase was comparison of erythroid and platelet parameters with results from a Coulter Counter Model S-Plus IV. The third phase consisted of comparison of the trimodal leukocyte differential count of the Toa E-5000 in 300 patients with four other differential methods. The first-phase studies showed excellent performance characteristics. Stability of samples at room temperature was good for a minimum of 12 hours, but storage for longer than 12 hours requires refrigeration to maintain stable values. The erythrocyte and platelet parameters showed good correlation with the Coulter S-Plus IV values except for the erythrocyte distribution width that is calculated differently. The third-phase studies are published elsewhere.