Detection of gamma-globin mRNA in fetal nucleated red blood cells by PNA fluorescence in situ hybridization.

Objectives: Fetal nucleated red blood cells (NRBC) that enter the peripheral blood of the mother are suitable for non-invasive prenatal diagnosis. The application of peptide nucleic acid (PNA) probes for tyramide amplified flow fluorescence in situ hybridization (FISH) detection of gamma-globin mRNA in fixed fetal NRBC is investigated.

Methods: Hemin-induced K562 cells or nucleated blood cells (NBC) from male cord blood were mixed with NBC from non-pregnant women and analysed using both slide and flow FISH protocols.