Chromosome doubling cells (CDCs) contain four sets of chromosomes. Tetraploid cells (CDCs originating from diploid cells) are recognized as precursor of cancers with chromosomal instability. CDCs arise in aneuploidy cells and facilitates epithelial-to-mesenchymal transition and more aggressive phenotypes. Cytometry is a useful technique in identifying the small number of CDCs arising in normal and cancer cells. However, cytometry technique measuring only DNA contents cannot distinguish CDCs. We developed the methods using image cytometry combined with Fluorescence in situ hybridization (FISH) for centromeres to identify the CDCs and elucidate proliferative capability by detecting CDC colonies. This article describes our developed methods and our fi ndings and discusses the importance of CDC analysis.
