Cell-free DNA blood collection tube is a special type of blood collection tube specifically designed for collecting blood samples to preserve and extract cell-free DNA.

1. Structural Features

• Material and Design:
  This kind of blood collection tube is usually made of high-quality medical plastics, such as polyethylene or polypropylene, which have good chemical stability and biocompatibility. The outer shell of the tube is sturdy and can withstand a certain degree of physical pressure, avoiding breakage during transportation and storage. The size of the blood collection tube is similar to that of ordinary blood collection tubes, which is convenient for medical staff to operate and for the use of blood collection equipment.
• Anticoagulant Components and Protectants:
  It contains specific anticoagulants inside, such as EDTA (ethylenediaminetetraacetic acid) or heparin, to prevent blood from clotting. This is crucial for the preservation of cell-free DNA, as the blood clotting process may affect the integrity and extraction efficiency of cell-free DNA. Meanwhile, it also contains special protectants that can stabilize cell-free DNA and prevent it from being degraded by nucleases. The components of the protectants may be a combination of certain biochemical reagents, such as specific buffers and nuclease inhibitors, which play a key role in maintaining the structure and quantity of cell-free DNA.
• Sealing System:
  The blood collection tube is equipped with a secure sealing system, such as a rubber stopper or a plastic stopper with a leak-proof design. This sealing system can effectively prevent the leakage of blood samples, reduce the contamination of samples by external factors, and ensure the safety and integrity of samples during collection, transportation and storage.

2. Uses

• Medical Diagnosis Field:
  In the early screening and diagnosis of cancer, the cell-free DNA blood collection tube plays an important role. For example, for certain cancers, such as lung cancer and colorectal cancer, tumor cells will release cell-free DNA into the bloodstream. By collecting patients’ blood samples using this kind of blood collection tube, these cell-free DNA can be effectively preserved. Subsequently, through genetic testing technologies (such as liquid biopsy), the tumor-related gene mutations in them can be analyzed to provide a basis for the early detection of cancer. In prenatal diagnosis, it can be used to detect the cell-free DNA of the fetus and conduct non-invasive screening for fetal chromosomal abnormalities (such as Down syndrome), reducing the risks brought by traditional prenatal diagnosis methods (such as amniocentesis).
• Research Purposes:
  In genetics and molecular biology research, the cell-free DNA blood collection tube is an ideal tool for sample collection. Researchers can use it to collect a large number of blood samples for studying variations in the human genome, gene expression regulation, and disease-related genetic markers, etc. For example, when studying the gene frequency of a certain genetic disease in a population, using this kind of blood collection tube to collect blood samples and extracting cell-free DNA from them for genotyping can efficiently and accurately obtain research data.

3. Precautions for Use

• Blood Collection Operation Specifications:
  Medical staff must strictly follow the principle of aseptic operation when using cell-free DNA blood collection tubes for blood collection. Before blood collection, the blood collection site should be cleaned and disinfected to prevent bacteria and other microorganisms from entering the blood samples. During the blood collection process, it is necessary to ensure the correct use of the blood collection tube. For example, the amount of blood collected should meet the requirements to avoid collecting too much or too little blood. Excessive blood may lead to insufficient anticoagulants and protectants, affecting the preservation of cell-free DNA; too little blood may not provide enough cell-free DNA for subsequent testing.
• Sample Storage Conditions:
  The collected blood samples should be stored at an appropriate temperature. Generally speaking, it is best to store them in a low-temperature environment (such as 2 – 8 °C) to slow down the speed of biochemical reactions and prolong the preservation time of cell-free DNA. If long-term storage is required, lower temperatures, such as -20 °C or -80 °C, may be needed, and repeated freezing and thawing of samples should be avoided, as the freezing and thawing process may damage the structure of cell-free DNA and reduce its quality and detectability.
• Sample Transportation Requirements:
  During transportation, it is necessary to ensure the stability of the blood collection tube and prevent it from being affected by severe vibration, collision or temperature changes. Usually, special sample transportation boxes will be used, which are equipped with appropriate cushioning materials and temperature control devices inside to ensure the safety and quality of samples during transportation. Meanwhile, samples should be labeled and recorded according to relevant regulations, including patient information, blood collection time, sample number, etc., so that subsequent processing can be carried out accurately when the samples are received.