Common problems of tripotassium EDTA in blood collection tube

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1. What is the coagulation mechanism of EDTA K3?

Answer: EDTA (ethylenediaminetetraacetic acid) and its salt is an amino polycarboxylic acid (salt). EDTA salt chelates calcium ions or other divalent ions in blood samples, blocking these ions from acting as a cofactor for thrombin, blocking and terminating the endogenous or exogenous coagulation process, thereby preventing blood specimens from clotting.

2. Does the tripotassium tube of EDTA need to be dried?

Answer: The tripotassium tube of ethylenediaminetetraacetic acid does not need to be dried, but each manufacturer can still formulate its own production plan according to their needs.

3. What is the recommended dosage of tripotassium EDTA as a common blood tube additive?

Answer: It is recommended to add 1.8mg per ml of blood as blood anticoagulant. The dosage of reagents can be seen in the following table.

EDTA K3 blood collection tube


4. What is the correct operation of the purple blood routine tube represented by EDTA K3 after blood collection?

Answer: EDTA K3 should be mixed upside down as soon as possible after blood collection for 5-8 times to prevent the formation of tiny blood clots. Especially when the blood collection temperature is higher than 25℃, the blood and EDTA K3 must be mixed in time, otherwise it will easily lead to blood coagulation or local coagulation.

5. Why do more than 100+ blood collection tube manufacturers in China choose the tripotassium produced by Desheng?

Answer: The tripotassium salt of ethylenediaminetetraacetic acid produced by Desheng is produced by ourselves and has independent intellectual property rights. The crystal has good morphology, high purity, and stable batch-to-batch difference. For many years, it has focused on serving more than 500 customers at home and abroad, has rich clinical experience, and is the best brand of choice for customers.

  1. EDTA K2 and EDTA K3 are additives for purple blood collection tubes, so what is the difference between the two?

Answer: See the following table for specific differences.


Tripotassium EDTA (EDTA K3)

Lithium heparin

Coagulation mechanism

Reversible chelation with calcium ions in the blood to achieve anticoagulation

Inactivates the action of serine protease by activating antithrombin Ⅲ, thereby preventing the formation of thrombin, and preventing platelet aggregation and other anticoagulant effects

Action stage

Endogenous or exogenous coagulation

Multi-stage in vivo or in vitro

Scope of application

Suitable for general hematology test, not suitable for coagulation test and platelet function test, nor for determination of calcium ion, potassium ion, sodium ion, iron ion, alkaline phosphatase, creatine kinase and leucine aminopeptidase , Suitable for PCR experiments.

Suitable for erythrocyte fragility test, blood gas analysis, hematocrit test, erythrocyte sedimentation rate and universal energy biochemical determination, not suitable for hemagglutination test. Excessive heparin can cause leukocyte aggregation and cannot be used for leukocyte counting. Because it can stain blood slices, the background is light blue, so it is not suitable for white blood cell classification.


7. Why do some EDTA K3 tubes show tiny coagulation fragments after blood collection?

Answer: This is because the local anticoagulant concentration in the EDTA K3 tube is too high, which causes some blood to enter the blood collection tube and cannot be fully mixed with EDTA K3, resulting in a small clot. This may be due to the failure to reversely mix the test tubes in time after blood collection.

8. EDTA K3 can be used as an additive for other tubes in addition to the purple cap.

Answer: Yes, it can be used in combination with sodium fluoride and separation gel. When EDTA K3 is used in combination with sodium fluoride, it can be used in blood sugar tubes, adding 1.2 to 2.0 mg per ml of blood. When EDTA K3 is used in conjunction with the separation gel, the dosage of tripotassium remains unchanged, and 0.8-1.2 grams of separation gel can be added to each tube.

9. What is the difference between tripotassium EDTA as an anticoagulant and the anticoagulant heparin salt?     

10. What are the storage conditions for dipotassium EDTA?

Answer: This product can be sealed and stored in a cool and dry place, protected from light, and can not be damp. The aqueous solution of this product can be sealed and stored at room temperature under sterile conditions. It is recommended that the aqueous solution of this product be ready to use immediately. Do not store it in a solution for a long time.