Abstract
We are focusing on fetal Nucleated Red Blood Cells (NRBC) as a target for noninvasive prenatal diagnosis. It is important to enrich fetal NRBC from maternal blood because the number of NRBC circulating in maternal peripheral blood is very small. We report here beneficial impacts of CD45 depletion and an automated detection system on the enrichment of NRBC. CD45 depletion using CD45-magnetic beads dramatically reduced the number of nucleated cells from a fraction after density gradient centrifugation. CD45 depletion enhanced the detection rate of NRBC as well as the detection efficiency. We used a Cytogenetic Scan System (Carl-Zeiss) to automatically detect and identify NRBC on slides. Compared with manual scanning under a microscopy, the automated scanning reduced time and labor and also increased the detection rate of NRBC three fold. The identified NRBC were analyzed by fluorescent in situ hybridization (FISH) to verify their sex in five cases. We definitely detected NRBC with XY signal in two out of two male cases.
