Quantitative method for free fetal DNA (deoxyribonucleic acid) proportion in maternal peripheral blood (patent number ZL201510225771.5)

The invention discloses a quantitative method for free fetal DNA (deoxyribonucleic acid) proportion in maternal peripheral blood. DNA containing designed SNP (single nucleotide polymorphism) in plasma is extracted by the aid of a designed primer and loaded on a machine after a series of treatment, sequencing products are compared to a human genome sequence, and a basic group of each SNP site is determined. The concentration of the free fetal DNA is quantified by analyzing the proportion of the basic groups in the SNP. Induced errors can be corrected by the aid of a plurality of SNP sites, the SNP sites are simultaneously calculated by a statistics method, and calculated free fetal DNA concentration accuracy is improved.