Confocal images were obtained using a Leica TCS SP5 microscope equipped with a HC PL APO CORR CS 40×/0.85 dry objective (Leica). For experiments on macromolecular partitioning, a small volume (2-5 µl) of Cstars extracted from capillaries prepared as described above was loaded into a glass microwell slide (Hamamatsu) containing 20 µl of fluorescent macromolecule prepared in TE buffer with 300 mM NaCl. Samples were sealed with DNase free tape (Grace Bio-Labs FlexWell SealStrips) to prevent evaporation, and left overnight to equilibrate. For excitation of sodium-fluorescein (FAM, Sigma Aldrich), fluorescein dextran conjugates (3kDa DXT-FAM & 10kDa DXT-FAM, ThermoFisher), and recombinant green fluorescent protein (rGFP, Sigma Aldrich) an Ar-ion laser (488 nm) was used, for excitation of rhodamine B (RhodB, Sig-maAldrich) and Ar-ion laser (514 nm) was used, and a HeNe laser (633 nm) was used to image Alexa Fluor TM 647 conjugated streptavidin (SAv-A647, ThermoFisher) containing samples. For each sample, we recorded confocal z-stacks of slice thickness 0.5 µm of 20-40 fields of view, each containing between 2-20 crystals. Penetration was quantified by the ratio of mean fluorescence intensity inside to outside the crystals, ξ, which was determined through manual masking of objects at their equitorial plane using the BioFormats plugin for ImageJ. The background level for ξ (grey band in Fig. ) was determined using solute-impermeable silica beads as reference (diameter 20 µm). For experiments on trigger-induced isothermal melting (Fig. ), samples were initially prepared as for all other C-star variants. A volume of trigger strand equivalent to a 1:1 molar ratio of trigger:bridge strand was added carefully in order not to disturb sedimented crystals. Directly after addition, a time series was recorded at 0.8 frames per second in transmission bright-field mode.