Development of an atomic force microscope for measuring mechanical properties of cell population

Biomechanical properties of cells have been identified as an important factor in various biological processes. As cells migrate collectively, they interact mechanically with their surrounding cells. Thus, it is crucial to quantify mechanical properties of cell population in a large scale from intra-to inter-cellular regions. To measure the stiffness of confluent cells in a large scale, we developed an atomic force microscope (AFM), with a wide-range scanner, equipped with a non-inverted (up-light) optical microscope. A liquid-immersion objective lens was employed to focus the laser light and collect the reflected light from a cantilever for optical lever unit. The AFM allowed us to map the height and the Young´s modulus of confluent epithelial cells (n ~ 200) in a range of about 300 μm × 300 μm.