Omcl tr400psahw

SCFS measurements were performed using a NanoWizard II AFM (JPK Instruments, Berlin, Germany) mounted on top of an Axiovert 200 inverted microscope (Carl Zeiss, Jena, Germany). For the cell mechanical properties measurements, standard pyramidal tipped cantilevers OMCLTR 400PSA HW (Olympus) had a nominal spring constant of 0.02 N/m. The cantilevers were calibrated by the thermal noise method before each experiment [30 (link)]. Cells were cultured on glass coverslips (ϕ 24 mm) for 24 h before the experiment. All experiments were performed at 37 °C using a temperature-controlled BioCell chamber JPK Instruments (Berlin, Germany). Force-distance curves were collected with a force load of 0.4 nN and at a rate of 2.5 μm/s. Measurements were always performed over the nuclear region of the cells. Five curves were acquired for every cell, and in every experiment, a minimum of 30 cells was analyzed. Force-distance curves were analyzed with JPK data processing software. Cell mechanical properties were acquired by evaluating Young’s modulus (E) of the cell, applying the Hertz-Sneddon model [31 (link)].

AFM imaging was performed using MFP 3D-BIO AFM (Asylum Research, Oxford Instruments) and utilizing cantilever OMCL TR400PSA HW (Olympus). Cells were cultured on glass coverslips (ϕ 24) for 24 h, then fixed with 4% formaldehyde in PBS and dried. Imaging was done in contact mode in the air. The scanning area was set to 90 µm, set point to 1 V, integral gain to 10, proportion gain to 0, scan rate 1 Hz, and 1024 scan points. Gwyddion software was used to analyze the obtained images.