Detection and relocation of cord blood nucleated red blood cells by laser scanning cytometry.
BACKGROUND
Fetal nucleated red blood cells (NRBC) present in the peripheral blood of pregnant women at low frequency are a potential target for noninvasive prenatal diagnostics.


METHODS
CD71-enriched cells from male cord blood (CB) were stained for the gamma chain of HbF (Hb-gamma) and cytocentrifuged. Fluorescence in situ hybridization (FISH) was done for the Y chromosome. Following staining of the nucleus with TO-PRO-3, laser scanning cytometry was performed. Artificial mixtures of small volumes of male CB and blood drawn from nonpregnant females were analyzed.


RESULTS
In CB, 59% of events double positive for Hb-gamma and TO-PRO-3 were identified as CB-NRBC. In contamination studies, male fetal CB-NRBC were identified perfectly on the basis of morphologic characteristics and FISH reactivity following relocation and visual assessment. Mean recovery was 8.7%.


CONCLUSIONS
Laser scanning cytometry of preenriched fetal NRBC may offer a promising way for noninvasive prenatal diagnostics. This is because it provides a virtual enrichment step and the position on the slides of cells visually confirmed to correspond to fetal NRBC is known. Further experimental procedures on well-defined and located target cells may be feasible.
Institute of Histology and Embryology, Karl Franzens University, Harrachgasse 21, A-8010 Graz, Austria.
Simone
S
Hennerbichler
Rudolf
R
Schmied
Erwin
E
Petek
Peter M
PM
Kroisel
Barbara
B
Pertl
Beate
B
Tiran
Gottfried
G
Dohr
Reinhold
R
Wintersteiger
Peter
P
Sedlmayr
D002467:Cell Nucleus / Q000378:metabolism; D041322:Chromosomes, Human, Y; D004900:Erythroblasts / Q000166:cytology*; D005260:Female; D005312:Fetal Blood / Q000166:cytology*; D006801:Humans; D019044:Image Cytometry / Q000379:methods*; D017404:In Situ Hybridization, Fluorescence; D007231:Infant, Newborn; D008297:Male; D018613:Microscopy, Confocal; D011296:Prenatal Diagnosis; D013194:Staining and Labeling