Data for "Variability of the mechanical properties of a single bone cell population"

Pre-processed data obtained by AFM nano-indentation of MLO-A5 pre-osteocyte cells. The data pre-processing consisted in contact point fitting, tip-sample separation correction and drift correction of raw data, all performed in MATLAB (v2016a).

The experimental methodology and data processing are described in the author's thesis (Chapter 3).

Methods

* AFM cantilever preparation
Tip-less cantilevers (Windsor Scientific) with nominal spring constant of 0.2 N/m were customised by glueing a silica bead (D = 6 μm, Bangs Laboratories) at the tip extremity.

* AFM set-up
A NanoWizard 3 atomic force microscope (JPK Instruments AG) coupled to an Eclipse Ti-S optical inverted microscope (Nikon Instruments) was used for all the experiments.
The cells were washed in phosphate buffer solution (PBS) and fresh medium was added. Samples were positioned on the heated sample holder to allow for testing at 37◦C.
Single cells were located through the coupled optical microscope and images of cell shape were recorded for morphological analysis.
The cantilever was centred over the location of interest and a grid of 5 points spaced 3 μm within each other was set. Force spectroscopy measurements were obtained on the 5-point grid for 3 times to collect a total of 15 data on each location. The relative set point and the approach velocity were set to 10 nN and 4 μm/s respectively.