Free DNA preservation solution: a key support for early screening of tumors

Early screening of tumors, as the name suggests, refers to the detection of early or even very early malignant tumors in healthy or high-risk populations. Traditional screening methods, such as imaging examinations, are often difficult to characterize small lesions; As the gold standard for diagnosis, tissue biopsy cannot be used as a large-scale screening method due to its invasiveness. It is in this context that liquid biopsy technology has entered the clinical field, and free DNA preservation solution is the basic support to ensure the practical application of this technology.

The tumor code in the blood

Circulating free DNA refers to highly fragmented DNA fragments that are free outside of cells in the blood. In a healthy human body, it mainly comes from normal cells undergoing aging and apoptosis. But when a tumor occurs, the situation changes. Tumor cells have a fast proliferation rate and high apoptosis rate, constantly releasing their DNA into the bloodstream. This free DNA from the tumor is called circulating tumor DNA.

This type of tumor DNA carries genetic variation information consistent with the primary tumor, including mutations, methylation, copy number variations, etc. In theory, with just one tube of blood drawn, signals from tumors throughout the body can be captured. However, this ideal state faces a serious challenge in reality: the tumor DNA content in the blood is extremely low. Especially in early cancer patients, tumor DNA accounts for only a very small proportion of total free DNA in plasma, sometimes even less than one thousandth. To extract these trace amounts of information from the vast background of blood cells, sample quality becomes the first step in determining success or failure.

The two major threats after leaving the body

After blood is separated from the body, the sample is not stationary. If there is no intervention, two problems will quickly occur. One is the instability of blood cells. After being isolated, nucleated white blood cells in the blood gradually undergo apoptosis or lysis, releasing a large amount of genomic DNA. These DNA do not come from tumors. When they flood into the plasma, they dilute the already extremely weak tumor signals like a flood. The second is the degradation effect of nucleases. There are naturally occurring nucleases in plasma, whose function is to clear free nucleic acids, which can lead to further fragmentation or even disappearance of valuable tumor DNA fragments.

Ordinary blood collection tubes are unable to address these two issues. In traditional EDTA tubes, blood must undergo plasma separation within a few hours, otherwise the sample will 'deteriorate'. For tumor early screening projects that require centralized testing or remote testing, this time window is obviously difficult to meet practical needs.

Triple function of preservation solution

The free DNA preservation solution is designed to address the aforementioned issues. It is pre sprayed on the inner wall of a dedicated blood collection tube and starts working from the moment blood flows into the tube. Its primary function is to stabilize blood cells. The preservation solution contains special cell metabolism inhibitors that can quickly act on white blood cells, preventing their rupture and release of genomic DNA. This is like closing the door to pollution at the source, ensuring that only the original free DNA in the blood is retained in the plasma. Secondly, it is to protect the existing DNA. The anti nuclease components in the preservation solution can inhibit the activity of nucleases, providing a layer of "protection" for free DNA to prevent its degradation. The third is to provide a transportation window. High quality preservation solution can keep samples stable at room temperature for up to 3 to 14 days. This means that the geographical distance between sampling points and detection centers is no longer a barrier, and remote areas can also enjoy detection services that are homogeneous with those in central cities.

Hubei Xindesheng Material Technology Co., Ltd. specializes in the production of blood collection tube additives. Since its establishment in 2005, it has a history of more than 20 years and has rich production experience. In addition to supplying high-quality free DNA preservation solutions, it can also provide a wide range of products such as serum separation gel, coagulant, heparin sodium, heparin lithium, silicification agent, etc., to meet the one-stop procurement needs of blood collection tube manufacturers! If you are interested, click on the official website to learn more details!