Hematology analyzer is one of the instruments widely used in clinical testing in hospitals. With the rapid development of science and technology, the technology of hematology analysis has also shifted from three classifications a few years ago to five classifications nowadays, and shifted to three dimensions from two-dimensional space, and at the same time, many of the five classifications of the modern hematology analyzers have adopted the advanced technologies, such as sheath flow technology, laser technology and so on. At the same time, many modern blood cell analyzers use advanced technologies such as sheath flow technology, laser technology, etc. The following on the five classification of blood cell analysis instrument detection methods and their applications are explained.
1 Impedance, laser scattering, and fluorescence staining techniques
The direct current impedance (DC) method is used to measure cell volume. Laser scattering produces forward-scattered light, side-scattered light and lateral fluorescence to detect the size of leukocyte volume, the condition of cellular contents (nucleus and granularity), and lateral fluorescence to reflect the content of intracellular deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), and the unique eosinophil detection lysing agent, Str-matolyzer-EO, lyses all the cells except for eosinophils or eosinophils, which are not detected. The unique eosinophil lyser Str-matolyzer-EO lyses or shrinks all cells except eosinophils, and the fluid containing intact eosinophils can be passed through a small well to be counted according to the resistive counting technique. In the basophil passage, the use of the special hemolytic agent Strmatolyzer-BA lyses or shrinks all cells except eosinophils, and fluids containing intact eosinophils can be counted by the resistive counting technique through small holes. Na?ve cell inspection channel (IMI) can be based on the phenomenon that na?ve cell membranes contain less lipids than the surface of mature cell membranes. Sulfated amino acids are added to the cell dilution suspension, and due to the different occupancy, more amino acids are bound to the surface of na?ve cells, which are resistant to hemolysing agents, and when hemolysing agents are added the mature cells are susceptible to be lysed while na?ve cells are not easily destroyed, and they can be detected by the resistive method. The graphs and data for the five classifications of leukocytes are obtained by combining the individual measurements. This technology is mainly applied in the series of hematology analyzers such as SE-9000, SE-9500, XE-2100, XT-1800, etc., which are researched and developed by Sysmex.
2 Electrical Impedance and Radiofrequency Conductivity Combined Detection Method
This method is to use four detection systems to detect different types of cells: (1) Lymphocytes, monocytes and neutrophils detection system: add hemolytic agent in cell suspension to make the erythrocytes dissolved, while the leukocytes are kept intact, the cytoplasmic and nuclear morphology approximates to physiological state, when these cells pass through the detection system, the resistance of the leukocytes is measured. When these cells pass through the detection system, the leukocytes are subjected to the combined detection of resistive antimetry (measurement of cell volume) and radiofrequency conductivity (detection of cell nuclei and particle density), which results in the classification of the cells into three groups, namely, lymphocytes, monocytes and neutrophils. (2) Eosinophils and basophils detection system: A special hemolytic agent is added to the cell suspension, and all cells except eosinophils and basophils are lysed or atrophied, and then the eosinophils or basophils that remain intact are counted. (3) Na?ve Cell Detection System: Sulfated amino acids are added to the cell suspension. Due to the different occupancy, the amino acids bound to the na?ve cells are more than those bound to the mature cells and are resistant to hemolytic agents; when hemolytic agents are added, the mature cells are lysed, and only the na?ve cells that may be present are retained for counting. At present, the NE1500 of Japan's East Asia company, SYSNEX company's SE9000 blood cell analyzer is to use this method for five classifications.
3 Multi-angle laser polarized light scattering detection method
Instruments using this technique use sheath fluid to dilute the specimen blood, the internal structure of diluted leukocytes approximates the natural state, only basophils due to their hygroscopic properties and the cellular structure of the cell has a slight change. The hemoglobin within the red blood cells is separated from the cells by the high osmotic pressure. The water from the sheath flow, on the other hand, enters the erythrocyte so that the cell membrane structure remains intact, and it has the same refractive coefficient as the sheath flow, which does not affect the detection of leukocytes. The instrument simultaneously detects the scattered light from cells passing through the laser beam from four angles; 0° front angle scattered light is used to determine the volume of the cells, 10° narrow angle scattered light is used to determine the structure of the cells, 90° vertically scattered light is used to make measurements of the internal cellular particles and cytoplasm, and 90° depolarized light scattering separates eosinophilic cells from neutrophils and other cells. The final results of all five classified instruments utilizing the above methods are presented on a high-resolution leukocyte distribution map. The use of computerized imaging techniques with various colored pixels representing certain cell concentrations makes cell subpopulations and abnormalities easily identifiable, and allows the isolated leukocyte subpopulations to be viewed from different orientations in three-dimensional space. By some kind of manipulation that rotates the three-dimensional axis, the distribution of cells in different orientations can be demonstrated.
4 Simple cell detection method using image analysis
This technique uses image analysis to stain a blood film, scan each field of view with a microscope containing a scanning lens, and analyze the acquired cell image against a standard image stored in the instrument to determine the type of the cell. This type of instrument requires a large computer system support, because at that time electronic computer graphics recognition and analysis technology is not very developed, so the development of this type of equipment received a certain degree of restriction, slow analysis speed, in the cell judgment accuracy is not satisfactory, not popular. Modern computer graphic image analysis technology, due to the rapid development of electronic computer computing speed, there has been great progress, if you can continue to develop such equipment, because it has a very intuitive, and human judgment of the cell analysis method is very close to the future should be promising.