Fig 2. Evolution of emerging actin networks induced by counterion condensation, depletion interactions and specific binding interactions.

Time-lapse images of emerging networks of actin bundles from semi-dilute solutions of confined actin filaments (3 μM, l _avg ≥ 10 μm) by (a) Mg²⁺ ions (50 mM), (b) PEG polymers (5% w/v, M. W. 8000) and (c) filamin dimers (ratio of filamin to actin (R) = 0.1). Images i-iv show the formation of networks while images v-viii show their disassembly upon addition and depletion of bundling agents respectively. Scale bar represents 10 μm.