Imaging flow cytometry and fluorescence microscopy in assessing radiation response in lymphocytes from umbilical cord blood and cancer patients.

DNA double strand breaks (DSB) induced by ionizing radiation (IR) are usually measured using γH2AX/53BP1 DNA repair foci, that is considered to be the most sensitive assay for DSB analysis. While fluorescence microscopy (FM) is the gold standard for this analysis, imaging flow cytometry (IFC) may offer number of advantages such as lack of the fluorescence background, higher number of cells analyzed, and higher sensitivity in detection of DNA damage induced by IR at low doses. Along with appearance of γH2AX foci, the variable fraction of the cells exhibits homogeneously stained γH2AX signal resulting in so-called γH2AX pan-staining, which is believed to appear at early stages of apoptosis.

BCR/ABL preleukemic fusion gene in subpopulations of hematopoietic stem and progenitor cells from human UCB.

The BCR/ABL preleukemic fusion gene (PFG) is one of the most frequent fusion genes in acute lymphoblastic leukemia (ALL) and was also detected in hematopoietic cells from umbilical cord blood (UCB) of healthy newborns. Since hematopoietic stem/progenitor cells (HSPC) are considered to be a critical cellular target for origination of leukemia, we have studied the presence of BCR/ABL PFG in expanded subpopulations of HSPC and differentiated cells from UCB of those healthy newborns, who have previously been tested positive for BCR/ABL by screening of their UCB mononuclear cells using RT-qPCR and FISH methods. We isolated cells from human UCB samples positive for BCR/ABL and negative controls.