Fig. 5.

Domain size transitions in four-component model systems. a Three-component phase diagrams for the Type I mixture DSPC/POPC/Chol (left) and the Type II mixture DSPC/DOPC/Chol (center) provide two faces of a tetrahedral phase diagram for the four-component mixture DSPC/DOPC/POPC/Chol (right). The parameter ρ describes the fraction of DOPC to total low-melting lipid. b Fluorescence images of giant unilamellar vesicles at 23 °C with composition DSPC/(DOPC + POPC)/Chol = 39/39/22 mol% reveal a domain size transition from uniform appearance (ρ < 20%) to modulated phase patterns (20 < ρ < 40%) to large round domains (ρ > 40%). Scale bars 10 μm. c Total integrated small-angle neutron scattering intensity versus temperature for 60-nm-diameter unilamellar vesicles with composition DSPC/(DOPC + POPC)/Chol = 39/39/22 mol%, for different values of ρ as indicated in the figure legend. Single phase control samples are shown in gray. d Domain radius versus thickness mismatch obtained from modeling the SANS data. Figure adapted from Heberle et al. (2014), Marquardt et al. (2015) and Usery et al. (2017)