The blood cell analyzer is mainly used for measuring the number of blood cells, the hemoglobin concentration and white blood cell classification, and giving each cell related parameter by calculation, which is one of the conventional devices with the highest usage rate in the clinical laboratory. The most common problem in the experiment is plugging holes. What are the causes of this problem? What is the relationship with the reagents used?

Principle of blood cell analyzer

The blood cell analyzer usually adopts the Coulter principle, that is, a platinum electrode is placed inside and outside the counting tube, and a constant current is applied between the two electrodes. The blood to be tested is first diluted with a clean electrolyte. In the electrolyte, it becomes a floating state, and then a negative pressure is applied to the upper end of the counter tube, and an electric pulse is obtained by the changing of the resistance when the blood cell through the gem hole of the counter tube, and the number of pulses represents the number of blood cells.

The blood cell reagent is used in combination with a blood cell analyzer for clinically detecting blood cell count, hemoglobin content and blood cell classification, and is an in vitro diagnostic reagent under the scope of medical devices, including diluent, hemolytic agent, washing solution, and anticoagulant. How the reagents used cause the plugging of blood cell analyzer?

How the reagents used cause the plugging of blood cell analyzers?

1. Diluent

Diluents are usually a class of isotonic solutions with acid-base buffering (common buffers including ADA, TRIS, HEPES, imidazole, etc.), appropriate ionic strength and conductivity can completely maintain the original volume of blood cells within a certain period of time. And obtain a pulse size corresponding to the cell volume.

Before performing blood cell analysis, the cleaning solution and the diluent are combined to clean the container and the pipeline of the instrument detection unit, thereby reducing the background value of the instrument and avoiding the interference of the previous detection sample on the detection. If the physical and chemical indicators of the diluent are unqualified, the cells will not be properly diluted in the interval, and the looseness will cause the cells to aggregate and easily cause the problem of plugging.

2. Hemolytic agent

After the diluted blood is added to the hemolytic agent, the red blood cells dissolve and release hemoglobin, which combines with the relevant components of the hemolytic agent to form a hemoglobin derivative, the derivative enters the hemoglobin detection system, and changes the at a specific wavelength and the hemoglobin content is in proportion with the absorbance. The instrument can display its concentration; at the same time, different types of white blood cells form a significant difference after the action of hemolytic agents, and the instrument can count the total number of white blood cells and the number of various groups according to these differences.

If the hemolysis is insufficient, the red blood cells are destroyed incompleted or the adhesion of red blood cell debris will adhere to the small holes. This situation continues for a long time, and the cell debris and protein deposits attached to the small holes will accumulate thicker and thicker, and then block the small holes.

3. Cleaning fluid

The composition of the cleaning solution generally includes high-quality amphoteric surfactant, animal hydrolyzed protease, preservative, sodium formate, sodium chloride, buffer such as ADA, TRIS, HEPES, imidazole and the like.

The main function of the cleaning solution is to clean the blood and protein in the instrument pipeline, reduce the cross-contamination of the blood, ensure the reliability and accuracy of the results, and provide a humid enough environment to quickly get from the entire flow system. And get rid of the bubbles. If the cleaning agent is not effective, it will not function properly, and it will inevitably cause the hole to be blocked for a long time. At the same time, in addition to the quality of the cleaning agent has an impact on the cleaning results, the cleaning method will also have an impact on the results, should be cleaned daily, weekly and monthly maintenance, so that the start-up test must be cleaned, the test results can be more accurate, The instrument can use longer.

4. Anticoagulant

The International Standardization Committee has recommended the use of K2EDTA as an anticoagulant for blood samples in blood cell counting and screening. It causes plugging for several reasons: the anticoagulation ratio is too high: it causes satellite phenomenon. Under the microscope, many small cells around the large cell can be seen, which makes the cell bulky and difficult to dissolve, which is easy to cause plugging; The time is too short: it takes time for the EDTA to react with the platelet clotting factor, which shortens with increasing temperature.

The blood analyzer liberates technicians from the original manual counting method, and also makes the test results more accurate, more efficient, more reproducible, less blood, greatly promotes the development of hematology testing technology andprovides more diagnostic informatio for clinical medicine. Through the attention to the details of the experiment, it is hoped to improve the service life of the instrument and the accuracy of the detection to better serve the patient.