Cellular Membrane Mechanics Analysis

A commercial atomic force microscope system (Dimension ICON, Bruker-Nano) was used to measure all the cellular surface plasma membrane properties. As previously published (42 (link)), an MLCT-C cantilever was used to measure the Young’s modulus of cells, with a spring constant at 0.01 N/m calibrated via the thermal tune method (Bruker-Nano). To avoid the substrate effect and keep consistency of the measurement conditions, all the measurements were performed at the top of the cell over the cell nucleus. The probe radius was calibrated by using a tip-radius calibration sample, and a silicon sample was used as the hard reference sample for all the indentation measurements. To minimize the cantilever drift due to the temperature fluctuation caused by the heating of the laser, the system was thermally equilibrated at 37°C for 40 minutes before the measurements.