Figure 5.

Simulation of optical tweezers experiment. Top: a visualization of simulation of optical trap experiment based on (25). A cell is allowed to adhere on a square adhesive pattern (green) to obtain a controlled spread size. Then, a spherical adhesive bead adheres to the cell until contact radius a_c is attained (left). Next, an external force F_app is applied to the bead, and its displacement x_c is recorded (right). Bottom: apparent Young’s modulus computed as E_app = 3F_app(8a_cx_c) in function of the cell radius for a cell with the estimated mechanical properties of an S180 cell (Table 1). Error bars indicate the SD across independent rotations of the cell. Inset: calibration of cell-bead adhesion energy w_cb = 0.517 nN/μm using the contact radius a_c. The dotted line indicates the experimentally observed contact radius. The shaded region indicates the SD across independent rotations of the cell. To see this figure in color, go online.