Image: UniCel DxH Slidemaker Stainer Coulter Cellular Analysis System (Photo courtesy of Beckman Coulter).
Although there have been advancements in instrumentation within hematology laboratories, there is still a need for review of a peripheral blood films (PBF).
Morphological assessment is extremely subjective and dependent on the acceptable standard of the film being assessed, and it is important to determine whether or not automated slidemaker-stainers are able to consistently and reproducibly prepare and stain blood films of exemplary quality, without carryover between specimens.
Hematologists at the London Health Sciences Center (London, ON, Canada) selected a total of 131 specimens, 46 morphologically normal and 85 hematologically abnormal, from their Health Center which specializes in cancer care, pediatrics, and obstetrics. A broad specimen pool of potential disease states was recruited from the day-to-day workload over an eight-day period. Four blood films were prepared manually and stained with the laboratory's routine method of Wright-Giemsa.
The scientists evaluated the UniCel DxH slidemaker stainer (DxH SMS, Beckman Coulter; Brea, CA, USA) which is a fully automated, integrated slidemaker, and stainer intended for the hematology laboratory. The DxH SMS is available either as a stand-alone instrument or part of the DxH workcell configuration. A unique patented device, the hemasphere, is incorporated into the system to measure “residual clinging” of the blood sample to an internal surface as an analogue for the way in which blood would behave as it is spread on a glass slide. Two samples were selected to perform this study evaluating the degree of cellular carryover that has the potential to occur in circumstances when a sample with extreme leukocytosis is followed by one with extreme leukopenia.
The investigators found that carryover was not an issue and repeatability was within expected limits. There was excellent agreement of the five-part differential between the automated blood films made by the DxH-SMS compared with the manually prepared reference blood film. There was no difference in identification and enumeration of blasts, variant lymphocytes, or nucleated red blood cells and red cell morphology showed excellent agreement.
The authors concluded that blood films prepared by the DxH-SMS are of excellent quality, the required cleaning requirements are simple, the software is intuitive, and the burden of quality related to the reagents is carried by the manufacturer. All of these reasons led them to believe they have made the right choice in incorporating the slidemaker/stainer into the configuration of their clinical instrumentation. The study was published in the April 2014 issue of International Journal of Laboratory Hematology.
London Health Sciences Center