Fig. 8 Single-cell force spectroscopy[122]
The AFM can measure the adhesion force of individual intact living cells
with high spatial and energy resolution, pico-cow-scale force
sensitivity, and nanometre-scale localization accuracy. AFM has unique
features: (1) it can operate in solution and observe biological
structures under in situ conditions [129]. (2) it
can observe individual proteins at a resolution greater than 1 nm,
allowing direct observation of structural changes in individual
biomolecules [128].
AFM also has limitations, such as the time-consuming and expensive
measurement of bacterial adhesion using single-cell force spectroscopy.
Only one cell can be characterized at a time; each cell requires a
separate cantilever and must be calibrated and functionalized[122,125,127], falling short of high throughput
measurements [128]. Using lectins to put fixed
cells on cantilever beams is time-consuming and tends to alter the
original physiological properties of the cells[126]. To obtain reliable data, a large number of
force-distance curves need to be measured.