FACS-based separation of maternal cells from umbilical cord blood. FACS-sorted cells, acquired with 2 HLA mAbs (mAb SN607D8-PE against child's HLA-A2 and mAb OK2F3-biotine against mother's HLA-A3), were processed for qPCR analysis. (A) In both the lymphocyte (CD14⁻CD45⁺) and monocyte (CD14⁺CD45⁺) population (2 middle plots), gated from the forward-sideward scatter (top plot), microchimeric cells could be detected, which are HLA-A3^pos and HLA-A2^neg (2 bottom plots). (B) Reference gene HCK, maternal DNA markers HLA-A*03, HLA-B*27 and HLA-DRB1*11, and child DNA marker HLA-A*02 were analyzed in quadruplicate with qPCR on an equivalent of 100 unsorted and sorted PBMCs.