Progression of cell cycle monitored by dielectric spectroscopy and flow-cytometric analysis of DNA content.

A dielectric method has already been developed for the real-time monitoring of cell cycle progression in synchronized cell culture (Asami et al., 1999). This method, in combination with DNA content analysis by fluorescence-activated cell sorting (FACS), was applied to the synchronized cell culture of a CDC28-13th mutant (Saccharomyces cerevisiae). In synchronous cell growth, relative permittivity epsilon (or dielectric constant) for the culture broth showed cyclic changes at low frequencies below 0.5 MHz, being correlated to phases in the cell cycle that were simultaneously determined by FACS. The epsilon increased in the period from S phase to G(2) phase and decreased between M and G(1) phases. Peaks in these cyclic changes of epsilon indicated the time when daughter cells segregated from mother cells.