| 描述信息 |
DNA was extracted from formalin-fixed paraffin-embedded (FFPE) tissue samples using the ReliaPrep FFPE gDNA Miniprep System (Promega, Madison, WI, USA). Blood samples were centrifuged in Streck tubes within 2 hours of collection at 1,600 g at 4 centigrade degree for 10 minutes. About 5 ml plasma supernatant was transferred to a new 5 ml microfuge tube and centrifuged at 16,000 g at 4 centigrade degree for 10 minutes to remove residual cells and debris. Supernatant was transferred into a new tube. Cell-free DNA (cfDNA) was extracted using the QiAmp Circulating Nucleic Acid Kit (Qiagen) following the manufacturer's instructions |