In modern clinical laboratory and life science research, the quality of blood samples is the cornerstone that determines the accuracy of test results. The standardization of each step from blood collection tube to analyzer directly affects the accuracy of diagnosis and the reliability of research. Among them, EDTA salts (such as dipotassium EDTA) are one of the most commonly used anticoagulants, and their application is not simply a "one plus one" process, but a set of fine processes that require strict adherence to scientific standards. Understanding and mastering the core precautions for its use is the key to achieving high-quality sample management and ensuring data credibility.
Core point: Standardized operation, starting from blood collection
The control of sample quality begins at the moment of blood collection. When using EDTA anticoagulant tubes, immediately, gently, and thoroughly invert and mix 5 to 8 times after blood collection. This action is crucial to ensure instant and complete contact between the anticoagulant and the blood, preventing local coagulation or the formation of small clots. Any uneven mixing can lead to anticoagulant failure, which in turn affects the accuracy of almost all subsequent blood cell analysis items, especially platelet count and white blood cell classification.
It is worth noting that the anticoagulant effect of EDTA is not permanent. It blocks the coagulation cascade by chelating essential calcium ions in the blood, and this process is reversible. Therefore, blood samples anticoagulated with EDTA are not a one-time solution. To ensure the reliability of the results, the test should be completed within 24 hours after blood collection. Beyond this time limit, even if no clots are visible to the naked eye, changes in the metabolism, morphology, and intracellular contents of blood cells may occur, leading to detection errors.
Shelf life: precise balance between temperature and time
Different testing items have different requirements for sample preservation conditions. Taking the most conventional blood cell analysis as an example: for white blood cell counting, the sample can be stored for 48 hours under 4 ℃ refrigeration conditions, but should not exceed 24 hours at 23 ℃ room temperature. Platelet count is more sensitive, and even in a 4 ℃ environment, it is recommended to complete the test within 24 hours after blood collection to prevent platelet aggregation or destruction. Clarifying these time windows is crucial for the laboratory to arrange the testing process reasonably and ensure that samples are analyzed at the optimal time.
Dose control: Both excessive and insufficient are inaccurate
The use of anticoagulants emphasizes "just right". Adequate EDTA is a prerequisite for ensuring adequate anticoagulation, but excessive EDTA may cause problems. Excessive concentration of EDTA may cause changes in the morphology of blood cells, such as red blood cell shrinkage and excessive white blood cell nuclear lobulation, which can interfere with the morphological recognition of blood smear microscopy and automatic analyzers. Therefore, strict control of the amount of EDTA dipotassium added (usually 1.5-2.0 milligrams per milliliter of blood) is a core step in the production process of blood collection tubes. At the same time, it should be noted that although EDTA can effectively inhibit platelet aggregation, it does not completely block it. Aggregation may still occur in certain individuals or pathological states and needs to be identified during testing.
Collaborative compatibility: expanding application scenarios
EDTA anticoagulant has good compatibility and can be combined with other additives to meet more testing needs. For example, when combined with sodium fluoride, it can inhibit glycolysis while anticoagulating, stabilize blood glucose levels, and is suitable for blood glucose detection. In such composite formulas, precise control of the ratio between the two is required, typically adding 1.2-2.0 milligrams of dipotassium EDTA and 2-4 milligrams of sodium fluoride per milliliter of blood. In addition, when combined with separation gel, it can effectively isolate serum/plasma from cellular components after centrifugation, facilitating stable transportation and storage of samples.
Hubei Xindesheng Material Technology Co., Ltd. has been researching and producing blood collection tube additives such as EDTA dipotassium for nearly 20 years. The performance of various products produced not only meets relevant standards, but also meets the customized needs of customers. If you are interested in our products, please click on the official website to learn more details or contact me!
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