The xCELLigence Real-Time Cell Analyzer (RTCA) System from Roche Applied Science utilizes impedance read-out to noninvasively quantify cellular status in real-time. Several cell-based applications have been developed for the xCELLigence System so far. Among them are cellular quality control, cell proliferation or cytotoxicity. In a recent study (1) the xCELLigence System was used to evaluate the influence of serum deprivation on synchronization of the murine mesenchymal progenitor cell line MuSC-E8.

Synchronization of cells means arresting the cells in a specific phase of the cell cycle. In most approaches, cells are arrested in the G0 phase in order to allow reentering of the cell cycle from a state of quiescence (G0), and, under carefully defined experimental conditions, move simultaneously into subsequent phases of the cell cycle (i.e., G1, S).

Following starvation over a certain amount of time, the cell cycle can be reentered by supplying the culture medium with 10% FCS. Using the technology of the xCELLigence

System, the optimal time point for reentering the cell cycle of starved MuSC-E8 cells was determined.

According to the authors, the xCELLigence System represents a very useful tool for detailed description and optimization of individual cell culture conditions of progenitor cell lines. In particular, the synchronization of cell lines by quiescence through serum deprivation can be optimized much more efficiently and conveniently using the xCELLigence System than traditional techniques such as end point proliferation assay or measuring DNA content by flow cytometry.