US20260132468
2026-05-14
Chemistry; metallurgy
C12Q1/6883
The described method involves a non-invasive approach to fetal genetic screening by analyzing fetal DNA present in maternal blood. This technique relies on diluting maternal blood samples to approximately 0.5 genome equivalent of DNA per reaction, enabling digital analysis to detect chromosomal aneuploidies like Down Syndrome. Traditional methods of detecting such conditions have required invasive procedures due to the inability of conventional PCR to identify chromosomal number changes in mixed DNA samples.
Digital PCR is central to this method, allowing for the separation of genomic material into discrete units for binary quantification. This process involves massively parallel amplification and detection techniques, examining up to 10,000 genome equivalents. By utilizing digital PCR, the method enhances sensitivity and specificity beyond traditional PCR, making it possible to detect chromosomal anomalies without invasive techniques.
The innovation leverages digital PCR's ability to amplify single molecules, followed by quantitative analysis. Various forms of digital PCR, including emulsion PCR and microfluidics, are mentioned as effective means to achieve the desired separation and quantification of DNA samples. These techniques facilitate the detection of aneuploidies by quantifying the presence of target sequences like chromosome 21.
The method builds on the understanding that fetal DNA comprises a small percentage of DNA in maternal blood. Previous efforts using PCR assays for fetal genetic screening have faced limitations due to sensitivity and specificity trade-offs. The present approach addresses these challenges by employing digital analysis to examine large numbers of chromosome samples, thus overcoming the constraints of conventional PCR in detecting chromosomal trisomies.
Several related studies and patents provide context and foundational knowledge for this method. Notable contributions include research on fetal DNA detection in maternal plasma, digital amplification techniques, and the quantitative analysis of fetal DNA for non-invasive prenatal diagnosis. These works underscore the reliability and potential of using cell-free fetal DNA for genetic screening.