Washing red blood cells with a low-speed centrifuge is convenient and quick.

Washing red blood cells is indispensable. Low-speed centrifuge ！

　　Red blood cells, also known as erythrocytes, are commonly abbreviated as RBC in routine laboratory tests. They are the most abundant type of blood cell and serve as the primary carrier of oxygen throughout the body in vertebrates via the bloodstream. In addition, they play an important role in the immune system. Mature red blood cells in mammals are nucleated-free, meaning they have lost their DNA. Red blood cells also lack mitochondria; instead, they generate energy by breaking down glucose. They transport oxygen and also carry a portion of carbon dioxide. When transporting carbon dioxide, they appear dark purple, whereas when transporting oxygen, they exhibit a bright red color.

　　Red blood cells are produced in the bone marrow. After red blood cells age, they tend to cause vascular blockages, so they automatically return to the depths of the bone marrow, where white blood cells take charge of their destruction. Alternatively, as they pass through the liver, macrophages break them down into bile.

　　The primary function of red blood cells is to transport oxygen and carbon dioxide. This is because red blood cells contain hemoglobin, which can bind with oxygen and deliver it to the tissues and organs that need it. At the same time, hemoglobin carries carbon dioxide—produced by the metabolism of tissues and organs—back to the lungs for exhalation. Hemoglobin is a conjugated protein formed by the combination of heme and globin polypeptide chains; it belongs to the class of pigment proteins and accounts for 32% to 36% of the total mass of red blood cells.

　　Hemoglobin consists of four polypeptide chains, including two α-chains and two β-chains. Each polypeptide chain surrounds an iron-containing heme group, which can bind either one molecule of oxygen or one molecule of carbon dioxide.

　　After centrifuging whole blood at low speed under sterile conditions, plasma is first separated and leukocytes are removed. Sterile physiological saline is then added to the red blood cells and thoroughly mixed. The mixture is subsequently centrifuged again to remove any remaining leukocytes. This washing procedure is repeated three times, ultimately removing more than 98% of the plasma, over 90% of the leukocytes and platelets, as well as metabolic byproducts such as potassium, ammonia, and lactic acid that accumulate during storage. More than 70% of the original red blood cells are retained. Finally, the red blood cells are suspended in physiological saline.

　　Remove impurity proteins to facilitate separation and purification in subsequent steps. It is primarily used for patients with transfusion-related allergic reactions, patients with autoimmune hemolytic anemia, hyperkalemia, and patients with hepatic or renal dysfunction.

　　The centrifuge is used to perform low-speed, short-duration centrifugation on blood samples. Remember: the higher the speed and the longer the duration, the more likely it is that white blood cells and lymphocytes will also sediment along with other components, thus failing to achieve the desired separation effect. For example, centrifuge at 500 r/min for 2 minutes, then use a pipette with a rubber bulb to carefully aspirate the upper layer of clear yellow plasma, leaving behind the lower layer of dark red erythrocyte suspension.

　　The quality of washed red blood cells prepared using a medical low-speed centrifuge meets the national standards and exhibits a higher hemoglobin content compared to those prepared manually, making it worthy of wider adoption and application.