Fig. 1: A complex coacervate library comprising pairs of oppositely charged peptides and nucleotides.

a Structures of negatively and positively charged molecules used as polyanions and polycations in evaluation of coacervation (the nucleotide terminal phosphates are dianionic at pH 8.0 with pKa ≈ 1 and ≈ 6. 8). b Combination of positively and negatively charged components led to a uniformly mixed solution, coacervation, or aggregation, depending on the details. c Optical microscope images illustrating samples categorized as uniform solution (white circles), coacervates (red circles) and aggregates (black circles); these particular samples are ATP with (Arg)n (n = 5, 30, and 100, left-to-right), corresponding to the points highlighted in panel e. Summary of findings for d (Lys)1–100 and e (Arg)1–100 with AMP, ADP, and ATP. The x- and y-axes go in the direction of increasing charge. Images are obtained over analysis of at least three independent trials and phase diagrams are result of these observations along with turbidity measurements. All scale bars represent 10 μm.