As shown by and Figure , the relative intensity ratios of hybrid PBd22-PEO14 GUVs have a monomodal distribution centred close to 0, indicating most GUVs are well mixed hybrid membranes, containing the expected average compositions of both the DiO and PBd22-PEO14-TMR probes. This data also indicates that there are no populations of pure PBd22-PEO14 polymer or pure POPC lipid vesicles in these samples. However the distributions are broad, indicating a significant range in individual GUV compositions centred around the mean composition of the sample.