2.4. DNA extraction
DNA was extracted using Plus Blood Genomic DNA Purification Kit
(GeneMark Diagnostics, Carlsbad, CA, USA) according to the
manufacturers’ instructions. NanoDrop 2000c spectrophotometer (Thermo
Fisher Scientific, Waltham, Massachusetts, USA) was used to measure DNA
concentration and purity at 260/280 nm in extraction samples. The
extracted DNA was stored at −20°C prior to testing.