Investigating the feasibility of laser-doppler vibrometry for vibrational analysis of living mammalian cells

The mechanical properties of cells are key indicators of the cell’s developmental state, their viability or can be a biomarker for pathogenesis such as cancer. State-of-the-art methods to analyze the biomechanical properties of cells are often contact-based like the atomic force microscopy. Laser-Doppler vibrometry (LDV), which optically determines the characteristic vibrational spectrum of investigated objects could be an alternative, non-invasive and non-destructive method to determine mechanical properties of cells and other biological samples. LDV is well established in the field of mechanical engineering, but only rarely used in other fields. Here we investigated whether LDV can be used to characterize and discriminate the mechanical properties of living mammalian cells. Using our current setup, which uses an LDV with a wavelength of 532 nm, we were not able to determine the cell’s mechanical properties, because of the low reflectivity of the low reflectivity of the cell in aqueous media at this wavelength. Nevertheless, by using confocal LDV setups or by staining the plasma membrane and using suitable bandpass filters in the optical path of the LDV, measuring the mechanical properties of living cells by LDV might be possible in future attempts.