New chamber format for chemotaxis experiments. (A) Chamber in 3-D view. The small observation area in the centre connects the two reservoirs along the y-axis. A cross-channel along the x-axis is used to fill cells in the observation area and thereby set up symmetrical initial conditions of cell distribution. The reservoirs are filled either with neutral or chemoattractant solution. (B) Design of the chamber in cross section (not to scale). Adherent cells placed into a small slit become superimposed by a chemoattractant from one side. Optionally, another group of adherent cells can be seeded into one large reservoir to produce chemoattractants. After cell seeding and filling, the chamber is closed by plastic plugs in order to prevent flow due to liquid evaporation. (C) Top view of the chamber with observation area (1), large reservoirs (2, 3), small side channels with filling ports for cell seeding (4, 5) and filling ports for the reservoirs (6, 7). (D) 3D view of the entire slide with three chemotaxis chambers. (E) Picture series showing the handling and filling procedure including cell seeding (1), filling of the entire chamber with chemoattractant-free medium (2 - 4), application of a chemoattractant (5, 6) and the final state for the assay (7).