Methodology

The Sysmex XN analyzers are an automated, quantitative, multi-parameter hematology analyzer for in vitro diagnostic use, employing hydrodynamic focusing (DC Detection), flow cytometry method (semiconductor laser), impedance, and SLS-hemoglobin methods. 

The analyzer, which uses a single aspiration pathway, provides a multi-parameter CBC by counting and sizing red blood cells and platelets using electronic resistance detection (sheath flow DC method). Hematocrit is directly measured as a ratio of the total RBC volume to whole blood (using cumulative pulse height detection), and Hemoglobin is converted to SLS-hemoglobin and read photometrically.

The white blood cell count, differential, reticulocyte parameters, fluorescent platelet (PLT-F), and nucleated red blood cells are all evaluated using flow cytometry with a semiconductor laser.  The laser exploits the differences in cell size, complexity, and RNA / DNA content. Forward scattered light provides information on blood cell size while lateral scattered light provides information on the cell interior (such nuclear size). Lateral fluorescent light intensity will increase as the concentration of the stain increases.  Fluorescent light is emitted in all directions and will be detected and measured by the XN.