Extended Data Fig. 6 |. Successive expansion-contraction cycles for a single ferritin crystal-hydrogel hybrid.

Light micrographs of a hybrid crystal at pre- and post-expansion stages in each cycle are shown on the left, and the corresponding changes in edge length upon expansion-contraction are shown on the right. The separation between the major ticks of the ruler is 100 μm. The crystal expands to a lesser extent during the first expansion cycle, which we ascribe to residual CaCl₂ (which forms strong polymer-polymer and protein-protein interactions) remaining in the solution that is transferred on the loop along with the crystal. The subsequent variability in the rate and extent of expansion is attributed to the different amounts of residual NaCl transferred in each cycle.