A Bayesian traction force microscopy method with automated denoising in a user-friendly software package

Abstract

Adherent biological cells generate traction forces on a substrate that play a central role for migration, mechanosensing, differentiation, and collective behavior. The established method for quantifying this cell–substrate interaction is traction force microscopy (TFM). In spite of recent advancements, inference of the traction forces from measurements remains very sensitive to noise. However, suppression of the noise reduces the measurement accuracy and the spatial resolution, which makes it crucial to select an optimal level of noise reduction. Here, we present a fully automated method for noise reduction and robust, standardized traction-force reconstruction. The method, termed Bayesian Fourier transform traction cytometry, combines the robustness of Bayesian L2 regularization with the computation speed of Fourier transform traction cytometry. We validate the performance of the method with synthetic and real data. The method is made freely available as a software package with a graphical user-interface for intuitive usage. Program summaryProgram Title: Easy-to-use TFM softwareProgram Files doi:http://dx.doi.org/10.17632/229bnpp8rb.1Licensing provisions: GNU General Public License v3.0Programming language: Matlab version R2010b or higherSupplementary material: A user manual for the software and a test data set.Nature of problem: Calculation of the traction forces on the surface of an elastic material from observed displacements.Solution method: Traction forces are efficiently calculated by combining L2 regularization in Fourier space with Bayesian inference of the regularization parameter.