Preliminary evaluation of the new hematology analyzer COULTER GEN-S in a university hospital.

The COULTER GEN-S system (COULTER Corp, Miami, USA) is an automated hematology instrument that is designed to provide a complete hematological profile including white blood cells (WBC), complete blood count (CBC) differential count (diff) and the reticulocyte parameters. It was evaluated in our laboratory over a one month period. A preliminary study was performed using the GEN-S software revision 1D. The evaluation had two purposes: 1) evaluation of the GEN-S specifications; 2) comparison of its analytical performance with the hematology analyzer currently used in our laboratory. The first part of the evaluation showed that the COULTER GEN-S is reproducible, has linearity beyond the specifications given by the manufacturer and produces stable results up to 48 hours after blood collection. The evaluation of analytical performance included: 1) a comparison between the GEN-S CBC and diff numerical results and the COULTER STKS (COULTER Corp, Miami, USA). These comparisons showed that the results given by the two methods are similar and suggested that the COULTER GEN-S could replace the current hematology instrument in use in our laboratory; 2) a performance analysis, to measure the system's ability to detect morphologic abnormalities, when compared to the reference blood smear examination. This part of the evaluation was performed on both normal and abnormal samples. The results of this analysis showed that the sensitivity of the GEN-S was excellent, especially regarding blast cells, immature granulocytes, nucleated red blood cells (NRBCs) and platelet clumps when using the complete suspect flagging system of the instrument. In addition, the use of the review criteria in our laboratory allowed to detect all hematological diseases. The overall false negative rate was 0.9%. Thus we consider that the COULTER GEN-S system is suited for use in medium-to large hospital laboratories which perform more than 100 CBC/day. Overall, the instrument had excellent performance, with a throughput of more than 100 samples/h. Its user friendly workstation has complete patient data management, which is in compliance with good laboratory practices in France.