Automated Assay for Fetal DNA Analysis in Maternal Serum

Abstract

Since the first demonstration of the presence of cell-free fetal DNA in maternal plasma of pregnant women (1), many reports have been published, mainly about fetal sex and RhD determinations (2)(3). Although good results have been obtained with conventional PCR, real-time PCR is now the most widely used amplification system for fetal DNA analysis because it allows high sensitivity with a high degree of protection against contamination (4). Conventional PCR may produce false-positive results from contamination (5), whereas real-time PCR, because it is a closed-tube system, reduces the risk of false-positive results from carryover of PCR products (6)(7). During sample preparation, however, contamination can result either from cross-contamination between samples or from the operator, particularly if a very small amount of human target sequence has to be detected, such as cell-free fetal DNA in maternal serum. We evaluated a fully automated …