Red Blood Cells and Platelets – RBCs and PLTs are counted in a dedicated channel using the direct current detection method with hydrodynamic focusing technology to minimize coincidence or recirculation. Automatic discriminators separate the two cell populations based on complex algorithms. The intensity of the electronic pulse from each analyzed RBC is proportional to the cell volume. The hematocrit (HCT) is directly determined based on the count and volume detection of each individual RBC. Even with samples at extremely low or unusually high concentrations, the Sysmex cell counters analyze RBCs and platelets with uncompromised precision and accuracy.
Hemoglobin Analysis – The Sysmex sodium lauryl sulfate (SLS) method for hemoglobin analysis is a non-cyanide method. Hemoglobin is determined in a separate channel, minimizing interference from high leukocyte concentrations. The SLS method shows excellent correlation with the reference method. With very short reaction times, this method is ideal for high throughput analyzers.
Fluorescent Flow Cytometry – Traditional flow cytometry is considered the best method for the differentiation of cell populations. However, it requires the use of costly antigen-antibody reagents and the procedures can be cumbersome and time consuming. Sysmex has refined basic techniques of flow cytometry and uses highly specific polymethine dyes to adapt that sophisticated technology to the high volume and automation requirements of the clinical lab. In order to meet the clinical demands for more accurate routine differentiation of normal and abnormal cells, flow applications using simple but sophisticated fluorescent dyes will continue to be expanded to fit the needs of routine CBC testing.
WBC Differential – Fluorescent labeling is a milestone for the routine WBC differential. Fluorescent measurement reveals the nucleus-plasma ratio of each individually stained cell, enabling the XE-Series analyzers to differentiate 6 reportable WBC populations. The combination of side scatter (inner complexity of the cell), forward scatter (volume) and fluorescence of nucleic acid material determines the classification of each WBC. The XE-Series utilizes an Adaptive Cluster Analysis System (ACAS) instead of conventional discriminators to separate cell populations into well defined clusters. This three-dimensional measurement of WBC provides an accurate and precise differential, even in highly pathological samples.
Reticulocytes and Platelets – Fluorescent technology is also used to offer efficient and reproducible analysis of the reticulocyte count and maturation stages. The advanced technology allows an accurate count of reticulocytes and fluorescent platelets, even in extremely low concentrations and in samples with giant platelets or red cell fragments. Due to higher fluorescent intensity of nucleated cells, such as leukocytes and nucleated red blood cells or red blood cells containing Howell-Jolly Bodies, these cells are distinctly separated from reticulocytes. The RNA/DNA content of reticulocytes decreases over time until they mature into erythrocytes that are without nucleic acid residues. A population of very early reticulocytes, the IRF (Immature Reticulocyte Fraction) is analyzed and reported, providing information about the rate of production of reticulocytes. In addition, measurement of the fluorescent platelets (PLT-O) can help resolve impedance platelet flags and reduce manual slide review.
Nucleated Red Blood Cells – The unique NRBC channel utilizes fluorescence and forward scatter light intensity to analyze each cell. These two parameters allow clear and reliable separation of leukocytes. NRBCs Leukocytes bind more dye to membrane and nuclear proteins than do NRBC. Consequently, leukocytes show much higher fluorescence than NRBC. The smaller volume of the NRBC nuclei results in a distinct pattern and separation of the WBC cluster from the NRBC cluster. Even at low concentrations, excellent precision and reproducibility for NRBC counts are achieved.