2.2. “Biological liquid application” software on ADVIA2120/2120i hematology analyzer

The “Biological Liquid Application” on ADVIA2120/2120i Hematology Analyzer is an in vitro diagnostic test for analyzing the total nucleated cell (TNC) and red blood cell (RBC) count in peritoneal, pleural, and PD fluid samples. The Body Fluid Application Default Run Screen displays 3 cytograms: peroxidase, basophil/lobularity, and RBC scatter cytograms. The TNC count is derived from the basophil/lobularity channel that, like the peroxidase channel cytogram, has been modified for the light scatter characteristics of body fluid cells. The basophil/lobularity cytochemical reaction consists of two steps: red blood cells and platelets are lysed, and all white blood cells except basophils are stripped of their cytoplasm using phthalic acid and a surfactant and the increased temperature in the reaction chamber. The stripped white cells can be categorized as MN or PMN cells based on the size (low‐angle light scatter, 2°‐3°) and complexity of their cell nuclei (high‐angle light scatter, 5°‐15°). As no specific controls for biological fluid samples are available, our daily quality controls were executed using blood‐based products (Siemens Healthcare Diagnostics Inc., USA). All automated cell counts were performed in the open manual (blood) mode. Samples analyzed without the dedicated software were processed with the default run screen for blood samples. All measurements on ADVIA2120 were performed according to the manufacturer’s specifications.27