Biomechanics with Bruker Atomic Force Microscopes

Only Bruker’s exclusive techniques, PeakForce QNM and FASTForce Volume, combine to provide the widest range of ramp frequencies and the most quantitative property mapping for biological samples. Additionally, higher imaging speeds and automated measurement capabilities, providing more data in less time, leading to faster time to publication.

Biomechanics chart

PeakForce QNM operating frequencies have been extended from 125Hz up to 1kHz in fluid and up to 2kHz in air in the BioScope Resolve.  In addition, FASTForce volume extends the operating frequency of linear ramps up to 300Hz.  The frequency gap between these two force mapping modes has been closed, facilitating direct comparison of force volume and PeakForceQNM data while opening up the possibility of investigating time dependent sample properties and behavior such as cell viscoelasticity.

One example of frequency dependent sample response is demonstrated with agarose gels of varying stiffness.  PeakForce QNM measurements were performed on three different agarose gels – 1.25%, 2.5% and 5% - at three different frequencies – 1kHz, 500Hz, and 250Hz. As expected, the resulting modulus values increased with the agarose gel percentage. Modulus values also increased in each of the gel types measured as PeakForce QNM frequency increased. The data demonstrates frequency dependent behavior of the gels which could suggest a viscoelastic effect.

 

There is relatively small standard deviation associated with each of the modulus values despite being taken by multiple users, using multiple probes, and multiple samples.  The data shows that there is very good consistency in the measurements, and that PeakForce QNM can be used to quantitatively measure sample behavior within a wide frequency spectrum.

PeakForce QNM modulus value variation