Free DNA preservation reagent and preparation method thereof

Abstract

The invention discloses a free DNA preservation reagent which comprises ethylenediamine tetraacetic acid potassium salt (EDTA (ethylene diamine tetraacetic acid) salt), formaldehyde, glycine, Tris- HCL, sodium chloride and deionized water. The cleaning agent comprises the following components in percentage by mass: 1.5-5% of the ethylenediamine tetraacetic acid potassium salt, 0.1-1% of the formaldehyde, 1-3% of the glycine, 5-10% of the Tris-HCL, 1-20% of the sodium chloride and the balance of deionized water. In addition, the invention also discloses a preparation method of the free DNA preservation reagent. The free DNA preservation reagent disclosed by the invention can be used for preserving complete DNA fragments and can be preserved for at least 3-5 days at room temperature, so that the preservation and transportation costs are greatly reduced.

Description

technical field [0001] The invention belongs to the field of life science and biotechnology, in particular to a free DNA preservation reagent and a preparation method. Background technique [0002] Circulating free DNA (cfDNA) is extracellular DNA fragments discovered in 1948, mainly derived from cell necrosis and apoptosis. The cfDNA released by tumor cells is usually called circulating tumor DNA (ctDNA), some of which can reflect tumor-specific characteristics, such as somatic mutations, etc. By detecting ctDNA, it can well represent the characteristics of the patient's tumor, and dynamically monitor the changes of ctDNA. The patient's disease recurrence and curative effect were evaluated. With the discovery of cell-free fetal DNA (cffDNA) in maternal blood, non-invasive prenatal screening (non-invasive prenatal) has been developed. The size of these free DNA fragments is concentrated in 100-300bp. According to many literature reports, generally EDTA anticoagulant tubes ...

AI Technical Summary

Problems solved by technology

The size of these free DNA fragments is concentrated in 100-300bp. According to many literature reports, generally EDTA anticoagulant tubes need to separate plasma as soon as possible after blood collection. It is best within 2 hours, degraded after 6 hours, and the content increases after 24 hours. It is because the cell-free DNA released after apoptosis in the blood collection tube increases, which will dilute the original cell-free DNA, especially for non-invasive production screening, the cell-free DNA released by the newly apoptotic cells is the cell-free DNA of the mother, which will Dilute the small amount of fetal cell-free DNA, resulting in detection failure or false negative

As mentioned above, it is best to separate the plasma immediately after the whole blood is collected in EDTA anticoagulant tubes, but some whole blood samples need to be sent out for testing, and the immediately separated plasma needs to be stored and transported on dry ice, which greatly increases the transportation cost

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