Method for purifying peripheral blood before cfDNA extraction

The invention relates to the technical field of blood purification. The invention provides a method for purifying peripheral blood cfDNA before extraction, which comprises the following steps: filtering blood by using a leukocyte removal filter, carrying out centrifuging, and extracting cfDNA after centrifugation. According to the purification method, the leukocyte removal filter is used for filtering after blood sampling, the number of leukocytes in the blood is reduced, and interference of a large amount of gDNA released due to leukocyte damage to experimental results is reduced. Compared with an existing experimental method for reducing gDNA interference by protecting white blood cells and reducing death and rupture of the white blood cells in the transportation process, the method has the advantages that the white blood cells are removed after blood collection, and the problem of interference caused by gDNA release due to death and rupture of the white blood cells in the transportation process is fundamen