The xCELLigence RTCA System from Roche Applied Science allows for label-free, continuous monitoring of cell phenotypic changes using electrical impedance as readout. The interaction of cells with the electronic biosensors leads to the generation of a cell-electrode impedance response, which indicates the status of the cells in terms of cell number, cell viability, cell morphology, and cell attachment quality. Real-time, continuous measurement ensures the documentation of cell phenotypes in the form of time- dependent cell response profiles (TCRP).
In a recent study, the utility of the Roche xCELLigence System was explored for assessing RNAi-mediated knockdown of gene function. Researchers focused on Eg5, a kinesin involved in the mitosis pathway. Their results provide evidence that real-time cell monitoring using the xCELLigence System is ideal for identifying the optimal time point for further molecular and biochemical analyses of cellular events. The study showed that transfection of siRNA targeted to Eg5 produces a transient cell phenotype, with maximum expression at 27 hours post-transfection.
The real-time online aspect of the xCELLigence System has made it possible to directly link phenotypic cellular events to the molecular and biochemical changes that occur after transfection with siRNA. Conventional analysis of the data at time points before or after 27 hours post-transfection would have missed this optimal window of opportunity for carrying out relevant gene and protein expression assays. Furthermore, the data stream of the xCELLigence System provides a continuous, label-free measure of cell culture quality control for transfection, simultaneously identifying potential off-target effects of the siRNA.
Filed Under: Drug Discovery