Multimode eight atomic force microscope

About 120–150 µm thick sections of live rat tibia bones were obtained by vibratome (Thermo Fisher Scientific) and mounted onto glass discs using silicone grease from the Bruker fluid cell accessory kit (Bruker). The force spectroscopy measurements were performed using a MultiMode eight atomic force microscope with a Nanoscope V controller and E scanner (Bruker). The regions of cells of interest for the acquisition of force-distance curves were selected under the optical microscope in combination with the AFM instrument.
The force-distance curves were acquired employing CP-PNP-BSG colloidal probes (NanoandMore GmbH, Germany) with a 5 µm borosilicate glass microsphere attached to the 200 µm cantilever. The spring constants of the cantilevers (measured by the thermal tune procedure) were 0.06–0.09 N/m.
All measurements were conducted at 25°C and all tissue was handled in DMEM/F12 HEPES-containing medium on ice. At least 70 individual force-distance curves were acquired for each type of cell by ramping over the surface and a total of 30 cells were measured from three different animals. These force-distance curves were processed with the NanoScope Analysis v.1.10 software (Bruker). Utilizing retract curves, the elastic modulus E was extracted from these force-distance curves by fitting in accordance with the Hertzian model of contact mechanics.

The AFM analysis was carried out with a MultiMode eight atomic force microscope equipped with a NanoScope V controller (Bruker Corporation, U.S.A.). The images for CLPs were obtained in tapping mode under ambient air condition with NCHV-A tapping mode probes (Bruker). The images for oil droplets (stabilized by chi-CLP and cross-linked with STP) were obtained in ScanAsyst mode under ambient air condition with SCANASYST-AIR probes (Bruker). Samples were prepared by dropping 5 μl of the diluted dispersion or emulsion on the mica surfaces and drying under ambient conditions. Nanoscope analysis 1.5 software was used for image analysis.