The FRAP measurements were conducted on a Nikon Confocal A1R+. The sample was prepared in acetate buffer (pH 4.8, 25 mM, 3 M NaCl) with pep4 (7.5 mM). The measurement utilized the inherent fluorescence of the peptide. The results are an average of eight different coacervates that were bleached with a 405 nm laser, and their fluorescence recovery was probed.