FIG. 2.

FEM simulations of the flow conditions and local concentrations in the microfluidic devices. Simulations shown here are for a vimentin flow speed (central inlet) of 335 μm s⁻¹ (40 μl h⁻¹) and salt buffer flow speeds for each lateral inlet of 310 μm s⁻¹ (80 μl h⁻¹). The mid-plane (x–y) is shown. (a) Vimentin concentration in the device. Enlarged are parts of the inflow of KCl (first cross) and MgCl₂ (second cross). The vimentin concentration remains high in the central part, since the large proteins diffuse slowly; the concentration drops from 4 mg ml⁻¹ to about 2 mg ml⁻¹ during the entire length of 10 mm. (b) Change in KCl concentration. KCl is injected at the first cross, diffuses into the central protein stream, and remains at a constant concentration when MgCl₂ is injected. (c) Change in MgCl₂ concentration. (d) Velocity magnitude.