Computational approach for modeling intra- and extracellular dynamics.

We introduce a phase-field approach for diffusion inside and outside a closed cell with damping and with source terms at the stationary interface. The method is compared to exact solutions (where possible) and the more traditional finite element method. It is shown to be very accurate, easy to implement, and computationally inexpensive. We apply our method to a recently introduced model for chemotaxis by Rappel et al. [Biophys. J. 83, 1361 (2002)].