Flow cytometry in analysis of cell cycle and apoptosis

The capacity for multiparametric measurement of large cell populations rapidly and accurately offered by cytometry has made this methodology indispensable in studies of cell proliferation and cell death. The reviewed cell cycle applications include (1) the univariate analysis of cellular DNA content for identification of G(0/1) versus S versus G(2)/M cells; (2) discrimination between noncycling (G(0); quiescent) and proliferating cells, based on the presence of proliferation-associated proteins; (3) identification of mitotic cells by histone H3 phosphorylation; (4) bivariate analysis of expression of cyclins D, E, A, or B1 versus DNA content; and (5) detection of DNA replicating cells and analysis of cell kinetics from the bivariate distributions of 5-bromo-2'-deoxyuridine (BrdU) incorporation versus DNA content. For the identification of apoptotic cells and discrimination between apoptosis and necrosis, flow cytometry techniques are applied to evaluate for changes in cell morphology, the presence of phosphatidylserine on cell surface, collapse of mitochondrial transmembrane potential, DNA fragmentation, and evidence of caspase activation. Semin Hematol 38:179-193.