Quantification of intracellular mitochondrial displacements in response to nanomechanical forces

Mechanical stress affects various aspects of cell behavior, including cell growth, morphology, differentiation, and genetic expression. Here, we describe a method to quantify the intracellular mechanical response to an extracellular mechanical perturbation, specifically the displacement of mitochondria. A combined fluorescent-atomic force microscope (AFM) was used to simultaneously produce well-defined nanomechanical stimulation to a living cell while optically recording the real-time displacement of fluorescently labeled mitochondria. A single-particle tracking (SPT) approach was then applied in order to quantify the two-dimensional displacement of mitochondria in response to local forces.