GSM5651526: LS190838; Homo sapiens; OTHER
Plasma was isolated from the whole blood sample using two-step centrifugation at 1500 ×g for 10 min and 13,000 ×g for 10 min. The supernatant was collected and stored at -80°C. Plasma DNA was extracted from 2 mL cell-free maternal plasma using the MagPure Circulating DNA Maxi Kit (Angen Biotech, Guangzhou, China) and eluted with 60 µL water. 1µL of DNA extract from cell-free maternal plasma was amplified using the barcoding primers of the following 12 Y-chromosome mini-STR loci: DYS439, DYS437, DYS643, DYS393, DYS570, DYS392, DYS549, DYS460, DYS458, DYS576, DYS438 and DYS533. The DNA library was prepared using KAPA Library Amplification Kit (Illumina, San Diego, CA, USA) according to the standard Illumina instructions, which mainly includes addition of specialized adapters and indexes to both ends of barcoding sequences.