Ethylenediaminetetraacetic acid dipotassium (EDTA-K₂) blood anticoagulant artifact

Blood analysis is a routine test item in clinical medicine. The vast majority of outpatients or inpatients are subject to this test. From the beginning of the development of manual detection to automatic detection. EDTA is an anticoagulant commonly used in hematology analyzer. It has good anticoagulant effect and little effect on blood cell morphology.

Potassium ethylenediaminetetraacetate (edta-k2)

Ethylenediaminetetraacetic acid (EDTA) is an amino polybasic acid. Because it can form complex with most metal ions, it has become a general strong chelating agent. In the past, the research on EDTA chelate and chelation mainly focused on three aspects

1. The most stable metal chelates of EDTA are transition elements and rare earth elements.

2. It is a group of vegetative compounds with medium complexing strength, such as alkaline earth metal complexes. Because it is difficult for common reagents to realize the complexation of alkali metals, EDTA has attracted special attention;

3. The affinity of EDTA to protons was studied through the sequence of EDTA itself and its co alkali metal salt.

Edta-k Ψ is a kind of amino polycarboxylic acid, calcium chelating agent, which has a great affinity for calcium in blood. It can effectively chelate calcium in blood samples, chelate calcium or remove the calcium reaction site. The decrease of calcium content will block and terminate the endogenous or exogenous coagulation process, so as to prevent the coagulation of hemostatic fluid samples. Every 0.8 mg can anticoagulate 1 ml of blood. It can not be used for the determination of Ca, Na and N in plasma. It is also suitable for anticoagulation. Edta-k Ψ can also complex some ions in plasma to make some proteins or nucleic acids more stable, but the interference of chromium complex formation on samples and experiments should be considered.

Edta-k Ψ is suitable for general hematological examination, especially for platelet count. Because it affects platelet aggregation and phagocytic function of blood cells, it is not suitable for coagulation and platelet function examination. It is also not suitable for determination of Ca +, K +, Na +, Fe +, alkaline phosphatase, creatine kinase and leucine aminopeptidase and PCR test.

Additives for vacuum blood collection: the additives for vacuum blood collection are edta-k2 aqueous solution, and 4mg edta-k Ψ is needed for anticoagulation of 2ml blood.

Because the concentration is small, in order not to dilute the blood, 20 μ l of water solution containing 200 g / L edta-k Ψ is usually preset in each blood collection vessel. Because the blood collection vessel is valid for two years, when the use environment changes slightly, such as the temperature changes, the water is easy to evaporate to the tube wall (especially the water in the solvent of plastic pet tube can seep through the tube wall and leak out), resulting in tube leakage Edta-k Ψ crystallizes quickly in the blood sample. When collecting blood, it is required that edta-k Ψ be reversed for at least 8 times, so that the crystallized edta-k Ψ can be fully dissolved and mixed in the blood. If the action is a little bigger, the red blood cells will be destroyed and hemolyzed, and the platelets will be aggregated, adhered and broken.