Development of a model system to compare cell separation methods for the isolation of fetal cells from maternal blood.

Three major methods have been described for the isolation of fetal cells from maternal blood: fluorescence-activated cell sorting (FACS), immunomagnetic beads, and magnetic-activated cell sorting (MACS). To date, no study has directly compared fetal cell recovery using each of these methods. Here we describe our system using a "model' male fetal cell mixed into female peripheral blood mononuclear cells. Fetal cell yields and purities were assayed by a quantitative polymerase chain reaction (qPCR) using chromosomes Y- and 7-specific sequences. Fetal cell recovery was investigated by selection of CD71+ cells or depletion of CD45+ cells. Our data demonstrated variation in fetal cell recovery for all methods tested, although CD71+ selection by FACS gave the best and most consistent results.