DNA was purified from whole blood by using the QIAamp DNA Blood Mini Kit (Qiagen, Inc., Valencia, CA, USA). Briefly, 20 µL protease and 200 µL buffer AL were combined with 200 µL whole blood and incubated at 56°C for 10 min. After incubation, 200 µL ethanol was added, and the entire mixture was applied to a QIAamp spin column. The purified DNA was eluted from the column with 70 µL nuclease-free water, and concentration was determined spectrophotometrically at optical density 260 nm.