Characterization of cell adhesion by the quartz crystal microbalance

The Thickness Shear Mode (TSM) quartz crystal resonator has been extensively used as a sensitive sensor in a variety of electrochemical and biomedical research. This technique based on the transverse shear mode oscillations provides a non destructive and a powerful means for probing changes at solid-solid or solid-liquid interfaces. Electrical impedance analysis is further better suited for modeling the loaded resonator systems near mechanical resonance and then gives quantitative information on the interfacial processes. The well established Butterworth-Van Dyke (BVD) equivalent circuit provides an excellent means for relating the electrical properties of the quartz to mechanical properties of the loading quartz surface. In the present study, kinetic of attachment and spreading of adherent living cells are investigated using the quartz crystal sensor technique. Experimental results of the motional resistance derived from the BVD equivalent circuit have shown that the increase in this parameter is strongly correlated with the evolving surface coverage during attachment and spreading processes of the adherent living cells on the quartz sensor surface. The dependence of the motional resistance on the cell concentration near resonant frequency is also analyzed. Finally, the acoustic experimental results are correlated to the cell counting technique.