The Working Principle of Cell – free DNA Blood Collection Tubes

In the field of modern medical testing, cell – free DNA blood collection tubes play a crucial role. Their working principle is based on the effective capture and stable preservation of cell – free DNA in the blood.

Cell – free DNA blood collection tubes usually contain special additives, which are the key to ensuring the stability of cell – free DNA. One common additive is a protease K inhibitor. Protease K can degrade proteins under normal physiological conditions. However, after blood collection, it may mistakenly target cell – free DNA for destruction. By inhibiting protease K, the cell – free DNA in the blood collection tube can avoid premature degradation.

In addition, buffers are added to the blood collection tube to maintain the acid – base balance of the blood sample. Cell – free DNA can maintain a stable structure only in a specific pH environment. The buffer keeps the pH value inside the blood collection tube within the range suitable for the preservation of cell – free DNA, generally between 7.2 – 7.4.

Regarding the collection process, when blood enters the cell – free DNA blood collection tube, the anticoagulant quickly takes effect to prevent blood clotting. The blood – clotting process can trigger a series of complex physiological reactions, which may lead to changes in the structure of cell – free DNA or entrapment of cell – free DNA in blood clots, making it difficult to be extracted for subsequent detection. The rapid action of the anticoagulant ensures that cell – free DNA exists in a free state in the plasma.

Meanwhile, the wall material of the cell – free DNA blood collection tube is specially treated to have low adsorptivity. Ordinary glass or plastic tube walls may adsorb some cell – free DNA, resulting in sample loss and affecting the accuracy of test results. The specially treated tube wall can minimize the adsorption of cell – free DNA, ensuring the integrity of cell – free DNA in the sample.

In terms of sample preservation, the cell – free DNA blood collection tube provides a relatively stable micro – environment for cell – free DNA. Even at room temperature, the cell – free DNA in the blood collection tube can remain relatively stable for several hours or even days, which buys time for the transportation and subsequent detection of the sample.

Through special additives, a suitable anticoagulation mechanism, a low – adsorptive tube wall, and a stable preservation environment, cell – free DNA blood collection tubes achieve efficient collection and stable preservation of cell – free DNA in the blood, laying a solid foundation for subsequent medical testing and research.