The invention provides a non-invasive fetal
trisomy 21 syndrome
prenatal screening kit based on digital PCR, and relates to the technical field of fetal
trisomy 21 syndrome screening, according to a method for enriching fetal cfDNA in pregnant woman
plasma, SPRIselect magnetic beads with low enrichment multiple and
silicon hydroxyl magnetic beads are combined for use, and under a certain dosage, the
recovery rate of fetal cfDNA short fragments reaches 95%; according to the provided multiple
system construction method, positive gDNA and negative gDNA are obtained on the basis of a 21
trisomy positive
cell line and a 21 trisomy negative
cell line, low-proportion reference substances are prepared and used, internal reference sites and detection sites which are high in detection capacity and stable in
detection performance are screened from the beginning, and compared with existing multiple
system establishment and
verification through direct use of pregnant woman
plasma samples, the multiple
system construction method has the advantages that the detection efficiency is high, and the detection cost is low. The to-be-detected sample with lower fetal cfDNA content can be stably detected.