Biospecimen collection, quality control, and processing
tumor, Tumor
TUMOR, TUMOR
Tumor and matched blood DNA were isolated from tumor samples and peripheral lymphocytes using TGuide M24 (Tiangen, Beijing, China). Absorbance at 260 nm (A260) and 280 nm (A280) was measured to estimate the purity and quantity of the total DNA by a NanoDrop 2000 spectrophotometer (Thermo Scientific, Wilmington, DE, USA). The extracted DNA was considered suitable for subsequent experiments if the A260/A280 ratio was between 1.6 and 1.9.