Cell – Free DNA Blood Collection Tube

A Cell – Free DNA Blood Collection Tube is a specialized type of blood collection tube designed specifically for the collection, preservation, and transportation of cell – free DNA (cfDNA) present in blood.

II. Structure and materials

1. Tube Structure
   • It typically has a standard – sized cylindrical body, similar to regular blood collection tubes, to be compatible with common blood – drawing equipment.
   • The tube is usually made of high – quality plastic or glass material. The choice of material depends on various factors such as cost, durability, and the need to prevent contamination.
2. Closure Mechanism
   • The tube is equipped with a secure closure cap, often with a rubber or silicone gasket to ensure an airtight seal. This is crucial for preventing evaporation of the blood sample and contamination from the outside environment.
3. Internal Coating
   • Many cell – free DNA blood collection tubes have a special internal coating. This coating serves multiple purposes.
   • It can prevent the adhesion of blood cells to the tube wall, reducing the release of genomic DNA from white blood cells. This helps to ensure that the collected sample primarily contains cfDNA.
   • Some coatings may also stabilize the cfDNA, protecting it from degradation due to enzymatic activity or other chemical reactions within the blood.

III. Functional characteristics

1. Preservation of cfDNA
   • The primary function of these tubes is to preserve cfDNA integrity. Once the blood is collected, the tube’s environment, including the preservative and the coating, helps to keep the cfDNA in a stable state for an extended period.
   • This allows for accurate analysis of cfDNA even if there is a delay between sample collection and testing.
2. Reduction of Genomic DNA Contamination
   • By minimizing the adhesion of blood cells and preventing the release of genomic DNA, these tubes improve the purity of the cfDNA sample.
   • High – purity cfDNA is essential for reliable molecular diagnostics, such as non – invasive prenatal testing (NIPT) and cancer liquid biopsy.
3. Convenience for Transportation
   • The secure closure and stable internal environment of the tube make it suitable for transportation over long distances.
   • Whether by road, air, or other means, the sample in the tube can remain intact, ensuring that the cfDNA can be analyzed at a specialized laboratory far from the collection site.

IV. Methods of use

1. Preparation
   • Before use, check the integrity of the tube and its packaging. Ensure that the closure cap is tightly sealed and there is no damage to the tube itself.
   • Prepare the necessary blood – drawing equipment, such as needles and tourniquets.
2. Blood Collection
   • Use standard blood – drawing techniques to draw blood into the cell – free DNA blood collection tube. The amount of blood collected usually depends on the specific requirements of the test, typically ranging from 2 – 10 ml.
   • Ensure that the blood is slowly and evenly injected into the tube to avoid hemolysis.
3. Post – Collection Handling
   • After blood collection, immediately close the tube tightly with the cap. Gently invert the tube several times to mix the blood with any preservatives or stabilizing agents present inside the tube.
   • Label the tube with relevant patient information, including name, date of collection, and any identification number.
   • Store the tube at the appropriate temperature (usually 4 – 25 °C depending on the manufacturer’s instructions) until it is ready to be transported to the laboratory.

V. Areas of application

1. Non – Invasive Prenatal Testing (NIPT)
   • In NIPT, cell – free DNA blood collection tubes are used to collect maternal blood. The cfDNA in the blood contains fetal DNA fragments. Analyzing these fragments can detect chromosomal abnormalities in the fetus, such as Down syndrome, without the need for invasive procedures like amniocentesis.
2. Cancer Liquid Biopsy
   • For cancer patients, these tubes are used to collect blood samples. The cfDNA in the blood may carry genetic mutations associated with cancer. Analyzing cfDNA can help in cancer diagnosis, monitoring treatment response, and detecting cancer recurrence.
3. Other Medical Research and Diagnostics
   • In addition to NIPT and cancer liquid biopsy, cell – free DNA blood collection tubes are also used in various other medical research and diagnostic applications. For example, in the study of autoimmune diseases, infectious diseases, and organ transplantation, cfDNA analysis can provide valuable insights.