Re: Fetal Cells in Maternal Blood
holzert@CENTOCOR.COM
Wed, 26 Jun 1996 13:30:07 -0400
Much work has been done recently trying to identify fetal cells in maternal blood as an
alternate to amniocentesis as a source of cells for genetic analysis. Targets most often
are fetal nucleated RBCs, trophoblasts or WBCs. Fetal nRBCs are believed to be present
in maternal blood at perhaps 1 in 10E6 or less. Most investigators attempt to enrich for
fetal nRBCs (by gradient purification at 1.077 or higher, followed by CD45 depletion
(magnetic beads or panning) and CD71 selection) and to characterize them as fetal by the
presence of fetal Hb (protein or message), Y chromosomes, paternal HLA, or other markers
under investigation. The fetal nRBCs isolate with maternal WBCs (and nRBCs) on Ficoll
and are resistant to lysis. To my knowledge, there are still no "unique" fetal makers on the
cell surface to differentiate them from maternal nRBCs other than patenal HLA.
As for flow, a method was recently published by Dorothy Lewis at Baylor College of
Medicine in Houston. Her E-mail address is: "dlewis@bcm.tmc.edu" The paper was:
"Rare Event Selection of Fetal Nucleated Erythrocytes in Maternal Blood by Flow
Cytometry" Cytometry 23:218-227, 1996.
In addition, Jim Leary at the University of Texas Medical Branch in Galveston has done
successful high speed sorting for fetal cells in maternal blood.
Tim Holzer
Diagnostics Division
Centocor, Inc.
Malvern, PA
(610) 889-4492 FAX (610) 889-4771
CD ROM Vol 2 was produced by staff at the Purdue University Cytometry Laboratories
and distributed free of charge as an educational service to the cytometry community.
If you have any comments please direct them to Dr. J. Paul Robinson, Professor & Director, PUCL,
Purdue University, West Lafayette, IN 47907. Phone:(317) 494-0757; FAX (317) 494-0517; Web http://www.cyto.purdue.edu
EMAIL robinson@flowcyt.cyto.purdue.edu
