Cell Mechanics: Combining Speed with Precision.

The mechanical response of cells is a powerful biophysical marker for cell state. Information on a cell’s elasticity can, for instance, be used to distinguish between different cell phenotypes, or between healthy and diseased cells. Depending on the application, either the accuracy or the speed at which cell properties can be accessed is more important. However, it is still difficult, as of this writing, to measure the mechanical properties of cells both at high speed and with high precision. In this issue of Biophysical Journal, Mietke et al. (1) present a combined theoretical and experimental study that might just bring us an important step closer to this goal of combining speed with precision in cell mechanics. The methods that are available as of this writing for measuring the mechanical response of cells can be roughly divided into static methods, where mechanical properties are measured for one cell at a time, and continuous flow methods, where the properties of many cells are probed in a continuous flow, using microfluidic devices. One of the earliest static methods to be developed was the so-called cell poking device (shown schematically in Fig. 1 a) (2), where a carefully calibrated thin and flexible glass rod is used to directly press on a single cell, enabling the controlled application of forces in the picoNewton regime. Atomic force microscopy (3) (Fig. 1 b) has also been used in a