What Are EDTA Blood collection Tubes and How Are They Used?

In medical testing and clinical diagnosis and treatment, EDTA blood collection tubes, as the key consumables for blood collection, play an important role in guaranteeing the integrity of samples and the accuracy of testing. In this article, we will comprehensively analyze this “invisible guardian” in the medical field from the aspects of definition, color classification, anticoagulation principle, testing purpose and use standard.

What is EDTA blood collection tube?

EDTA blood collection tube is a kind of vacuum blood collection tube containing Ethylene Diamine Tetraacetic Acid or its salt, which is mainly used for the collection of blood samples and anticoagulant treatment. EDTA can block the coagulation cascade reaction by chelating the calcium ions in the blood, so as to keep the blood in a liquid state for a long time, and provide stable samples for the tests of blood routine and molecular biology. It provides stable samples for blood routine, molecular biology and other tests.

As an important part of medical consumables, EDTA blood collection tubes need to comply with the national standard of “Single-use venous blood sample collection containers” (e.g. GB/T 19489-2008) to ensure the performance of sterility, non-pyrogenic and non-cytotoxicity.

Different colors of EDTA blood collection tubes

According to international common standards (such as CLSI H3-A6 guidelines), EDTA blood collection tubes are usually capped in purple (EDTA-K2/K3) or blue (sodium citrate mixed with EDTA) to differentiate the use:

Note: Some brands may be coded in other colors, check the instructions before use.

Anticoagulation mechanism of EDTA blood collection tubes

EDTA through its molecular carboxyl group (-COOH) and calcium ions in the blood (Ca²⁺) combined to form a stable chelate, thus inhibiting the activation of plasminogen, blocking the coagulation process of fibrinogen into fibrin. This anticoagulation has the following characteristics:

1. rapid onset of action: anticoagulation can be completed within 1-2 minutes after blood collection;

2. high stability: samples can be stored for more than 48 hours (refrigerated can be extended to 72 hours);

3. Wide range of application: suitable for most hematology tests, but not for coagulation or platelet function tests (sodium citrate tubes are required).

 Core testing items of EDTA blood collection tube

1. routine blood analysis: white blood cell count, red blood cell parameters, hemoglobin concentration, etc;

2. blood group identification and cross-matching: ABO blood group, Rh factor detection;

3. molecular diagnosis: genetic testing, viral load determination (e.g. HIV, HBV);

4. glycated hemoglobin (HbA1c): long-term blood glucose monitoring for diabetes mellitus;

5. blood parasite screening: Plasmodium, microfilariae detection.

Use of norms and precautions

1. Collection process:

 After disinfecting the skin, operate according to the standard of venous blood collection;

 Immediately after collection, invert the blood collection tube 5-8 times to ensure that the anticoagulant is fully mixed with the blood;

 Avoid violent shaking (to prevent hemolysis).

2. Storage and transportation:

 Store at room temperature (15-25°C), avoid heat or freezing;

 Place vertically during transportation to prevent loosening of the tube cap.

3. contraindication scenarios:

 Sodium citrate tubes are required for Coagulation IV (PT, APTT, etc.);

 Platelet function test requires sodium citrate tube.

How to choose high quality EDTA blood collection tube?

1. Qualification and certification: choose products that have passed ISO13485 and CE certification. 2;

2. Material safety: the tube body should be transparent and free of plasticizer residue;

3. Accurate dosing: the amount of anticoagulant added should be in line with the national standard (e.g. EDTA-K2 concentration of 1.8±0.15mg/mL);

4. Brand reputation: Priority is given to well-known brands in the field of medical consumables to ensure batch stability.

Conclusion

As a key member of blood collection device, EDTA blood collection tubes have a direct impact on the accuracy of test results in terms of their anticoagulant properties. By standardizing the use of different color-coded blood collection tubes and combining them with strict collection procedures, it can provide a reliable basis for clinical diagnosis. In the future, with the development of precision medicine, EDTA blood collection tubes will play a more important role in blood analysis, gene sequencing and other fields, and continue to protect human health.