3.

Multiphase coacervate pH sensitivity. a,c) Confocal fluorescence microscopy images of pAsp multiphase coacervates at ∼pH 5.7 (a) and at pH 4.7 (c). b,d) Corresponding bar plots of the relative intensity of each of the fluorescently tagged cations DEAE-dextran-FITC (green), pLys-Rhodamine (red), and pHis-Alexa Fluor 633 (blue) in the coacervate multiphase at ∼pH 5.7 (b) and ∼pH 4.7 (d). Intensities are normalized such that 100% corresponds to the maximum intensity across all dyes and all phases; other dyes and phases are scaled relative to this value. A minimum of 20 measurements were collected per phase. Error bars represent standard deviations. Scale bars are 10 μm (full image) and 2.5 μm for the magnified image that represents the area of the dashed white line box. Error bars in b,d represent standard deviations of a minimum of 20 droplets. e) Schematic representation of the pH-mediated rearrangement of polyions in the multiphase.