Performance of Sysmex SP-50 automated slidemakers and stainers in three hematology laboratories

Manual differential count and morphological evaluation of leukocytes remain the gold standard for white blood cell differential (WBC DIFF). However, the accuracy of manual WBC DIFF depends on the quality of the blood slide and the observer's expertise. Nowadays, automated slide preparation and staining systems, such as Sysmex SP-50, have been introduced to improve the quality of this method. In this study, we evaluated the quality of peripheral blood smears prepared and stained using the SP-50 automated system, with a particular focus on variables affecting cell distribution and morphology. This study evaluates the performance of five Sysmex SP-50 systems, from analyzer installation to final verification. The verification protocol included a preliminary performance check of all analyzer setups, followed by a conclusive verification. Conclusive verification was initiated after the performance checks were considered acceptable by laboratory professionals. The results demonstrated cell maldistribution across the film and the presence of smudge cells, both of which were linked to the pressure and height/angle of the spreader glass. In addition, inadequate staining of the blood film was observed, which was influenced by staining conditions and the use of fans. Together, these findings highlight critical quality issues with blood smear preparation that compromise accurate morphological analysis. The results suggest that while automation may offer some advantages, the quality and reliability of Sysmex SP-50-generated smears need laboratory-specific adjustment to meet the quality standards required for diagnostic evaluation.