ABSTRACT
Objective To explore the causes of accidental instability of SYSMEX XS-800i blood cell analyzer for WBC testing and their countermeasures.Methods Totally 10 pieces of specimen with high deviation were analyzed retrospectively, and the changes of DIFF-Y values of WBC were observed. Sysmex detergent was used to clean the pipelines including 4DL, 4DS and EPK pipes. Fluid path electromagnetic valve was checked and then repaired or replaced. Results It's proved that the results at the first time were not reliable, and there was significant differences between the results at the first and second times for DIFF-Y value, with P<0.01. The failures were eliminated after the above countermeasures were carried out.Conclusion WBC testing pipelines and electromagnetic valve of fluid path have to be cleaned periodically to eliminate the influence on DIFF-Y value of WBC and false increase of WBC counting.