Rapid non-invasive prenatal screening test for trisomy 21 based on digital droplet PCR.

Non-invasive prenatal tests for the detection of fetal aneuploidies are predominantly based on the analysis of cell-free DNA (cfDNA) from the plasma of pregnant women by next-generation sequencing. The development of alternative tests for routine genetic laboratories is therefore desirable. Multiplex digital droplet PCR was used to detect 16 amplicons from chromosome 21 and 16 amplicons from chromosome 18 as the reference.

Digital polymerase chain reaction duplexing method in a single fluorescence channel.

The digital polymerase chain reaction (dPCR) technique can quantify specific sequences of deoxyribonucleic acid using either a droplet-based or chip-based system. dPCR duplexing methods in a single fluorescence channel are typically based on the difference in fluorescence amplitude (F) between two targets. The different targets are distinguished from each other by the F-value variation using non-equal probe concentrations or different target lengths.