Monitoring cell cycle by impedance spectroscopy: experimental and theoretical aspects

Lack of accurate measurements and disuse of appropriate models (taking into account that during cell cycle, cell shape is often neither spherical nor ellipsoidal) confined most practical applications of impedance spectroscopy (IS) on cell suspensions to biomass monitoring (e.g., at whisky and beer fermentation). The significant influence of cell shape on the dielectric behaviour provides IS a new and promising challenge: to monitor the cell cycle progression. Our experience on arbitrarily shaped cells has been applied to simulate the evolution of a suspension of initially synchronised budding yeast. We have taken into account that until 'Start' the shape is fairly spherical. In agreement with the actual information on cell cycle, we have assumed that cytokinesis leads to the emergence of two differently sized cells:'mother' and 'daughter', that after 'Start' are considered to process identically. Impedance measurements have been performed on synchronised suspensions of the budding yeast mutant, CDC 28 over several cell cycles. The agreement of simulated with real data is illustrated with several examples. (C) 1998 Elsevier Science S.A. All rights reserved.