Measuring Cellular Traction Forces with Micropillar Arrays.

Accurately evaluating cellular forces is critical for studying mechanosensing and mechanotransduction processes, and it necessitates sensitive measurements on the piconewton scale. Here we describe a specialized method that employs elastic polydimethylsiloxane (PDMS) micropillar arrays, which cells can adhere to and bend. The flexibility of the pillars correlates with their heights; the longer they are, the easier they are to bend. Thus, an array of taller pillars mimics a relatively soft substrate that readily yields in response to cellular forces. Tracking cell movements and pillar displacements using live-cell microscopy enables the calculation of cellular forces and the tracking of their dynamic features throughout early and late stages of cell spreading on the pillars. This technique offers the advantage of high spatial and temporal resolution analyses and constitutes a method to investigate the effect of substrate rigidities on cellular functions.