Mechanical properties of single cells-measurement possibilities using time-resolved scanning acoustic microscopy

The interconnection between biochemical and mechanical processes inside cells, particularly cardiac cells, is of fundamental interest in biology and medicine. Scanning acoustic microscopy (SAM) allows the study of elastic properties of biological cells. However, conventional SAM is too slow to trace fast variations of cardiac cell mechanical properties during contraction, and low frequency time-resolved SAM used in biology and medicine does not provide enough resolution to study the elasticity of a single cell. In this report, we present the primary results obtained by the time-resolved, high frequency acoustic microscope on quantitative measurements of the local mechanical properties of single cultured cells in vivo. A Fourier spectrum approach is applied to determine the effect of the SAM characteristics, such as frequency response and semi-aperture angle of the lens, on the accuracy of the elastic properties' measurements. The potential of our approach is discussed through the investigation of the cytoskeleton of different cell lines and the contraction apparatus of cardiac muscle cells.