We have developed an optical method for real-time monitoring of cellular motion in a natural environment with nanometer resolution. From the motion driven by small optical forces, we measured dynamic viscoelastic responses of living cells in the linear reversible region. Cytoplasmic gel-to-sol transition that was due to the disruption of the actin-filament framework was detected, and a linear release of Ca<sup>2+</sup> from intracellular storage that was related to submicrometer cell deformation was observed. The method was shown to be a powerful tool for studying the natural response of cells to mechanical perturbation.
© 1998 Optical Society of America
Chau-Hwang Lee, Chin-Lin Guo, and Jyhpyng Wang, "Optical measurement of the viscoelastic and biochemical responses of living cells to mechanical perturbation," Opt. Lett. 23, 307-309 (1998)