The blood analyzer is mainly used to detect various blood cell counts, white blood cell classification and hemoglobin content. The detection principle includes two major principles of electricity and optics. Electrical principles include electrical impedance method and radio frequency conductivity method; optical detection principles include laser scattering method and spectrophotometry.
The principle of blood count
1. Principle of electrical impedance method: blood cells are poor conductors. When the blood cell suspension diluted with isotonic electrolyte solution passes through small holes with stable current on both sides, the electrical resistance in the small hole sensing area increases due to the lower conductivity of the cells than the electrolyte solution. Instantly cause a voltage change to generate a pulse signal, that is, a pass pulse. After the pulse signal is amplified, discriminated, and reshaped, it is sent to the counting system to obtain the cell counting result. According to the pulse size, the cell volume can also be analyzed, and the cell volume distribution graph can be provided.
2. The principle of flow cytometry and light scattering blood cell detection: Using flow cytometry, when the sheath fluid gathered by a single cell along with the hydrodynamic force passes through the detection area irradiated by the laser, the beam is refracted, diffracted and scattered, and the scattered light is caused by The photodetector generates pulses after receiving. The pulse size is proportional to the size of the illuminated cells. The number of pulses represents the number of cells.
