Ij. Vanwijk et al., MULTIPARAMETER IN-SITU ANALYSIS OF TROPHOBLAST CELLS IN MIXED CELL-POPULATIONS BY COMBINED DNA AND RNA IN-SITU HYBRIDIZATION, The Journal of histochemistry and cytochemistry, 43(7), 1995, pp. 709-714
We developed a non-radioactive assay for simultaneous detection of cyt
oplasmic mRNA and nuclear genomic DNA in fetal trophoblast cells by se
quential in situ hybridization. Trophoblast-specific mRNA is detected
with a digoxigenin-labeled RNA probe complementary to HLA-G, followed
by visualization through the generation of stable contrast-rich DAB/Ni
complexes. Genomic target DNA is subsequently visualized in labeled c
ells by fluorescent in situ hybridization using biotin-labeled chromos
ome-specific DNA probes. Simultaneous visualization of both targets is
made possible using a fluorescence microscope with FITC filter and co
nventional brightfield light, This method allows detection of trophobl
ast cells within a mixed cell population and, at the same time, analys
is of chromosome anomalies in the trophoblast cells identified. For pr
enatal diagnosis of fetal cells enriched from maternal peripheral bloo
d during pregnancy, this multiparameter in situ analysis of immobilize
d fetal trophoblast cells will be very useful.