Insights into monitoring changes in the viable cell density and cell physiology using scanning, multi-frequency dielectric spectroscopy

• Dielectric spectroscopy (DS) is now the most common method for estimating the in situ live cell concentration in animal cell culture. • DS and traditional offline methods for cell counting based on Trypan Blue correlate well during the growth phases but with some cell lines, deviations are observed during the late growth phase. • Scanning multi-frequency DS can detect the physiological changes of the cells during the death phase of the culture including changes in cell size, membrane capacitance and internal conductivity [1-3]. • The concept of using the Area Ratio Algorithm (ARA) looks to be a relatively simple and promising method for providing on-line cell counts that correlate well with traditional methods for the complete cell growth cycle.