title: Preparing giant unilamellar vesicles (GUVs) of complex lipid mixtures on demand: Mixing small unilamellar vesicles of compositionally heterogeneous mixtures.
abstract: Giant unilamellar vesicles (GUVs) are simple model membrane systems of cell-size, which are instrumental to study the function of more complex biological membranes involving heterogeneities in lipid composition, shape, mechanical properties, and chemical properties. We have devised a method that makes it possible to prepare a uniform sample of ternary GUVs of a prescribed composition and heterogeneity by mixing different populations of small unilamellar vesicles (SUVs). The validity of the protocol has been demonstrated by applying it to ternary lipid mixture of DOPC, DPPC, and cholesterol by mixing small unilamellar vesicles (SUVs) of two different populations and with different lipid compositions. The compositional homogeneity among GUVs resulting from SUV mixing is quantified by measuring the area fraction of the liquid ordered-liquid disordered phases in giant vesicles and is found to be comparable to that in GUVs of the prescribed composition produced from hydration of dried lipids mixed in organic solvent. Our method opens up the possibility to quickly increase and manipulate the complexity of GUV membranes in a controlled manner at physiological buffer and temperature conditions. The new protocol will permit quantitative biophysical studies of a whole new class of well-defined model membrane systems of a complexity that resembles biological membranes with rafts.
authors.affiliation: MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, DK-5230 Odense M, Denmark; Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark. Electronic address: bhatia@memphys.sdu.dk.
authors.forename: Tripta
authors.initials: T
authors.lastname: Bhatia
authors.affiliation: MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, DK-5230 Odense M, Denmark; Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Husen
authors.affiliation: MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, DK-5230 Odense M, Denmark; Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Brewer
authors.affiliation: MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, DK-5230 Odense M, Denmark; Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Bagatolli
authors.affiliation: MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, DK-5230 Odense M, Denmark; Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark.
authors.forename: Per L
authors.initials: PL
authors.lastname: Hansen
authors.affiliation: MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, DK-5230 Odense M, Denmark; Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark.
authors.forename: John H
authors.initials: JH
authors.lastname: Ipsen
authors.affiliation: MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, DK-5230 Odense M, Denmark; Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark.
authors.forename: Ole G
authors.initials: OG
authors.lastname: Mouritsen
mesh_terms: D045424:Complex Mixtures; D008055:Lipids / Q000737:chemistry*; D018613:Microscopy, Confocal
chemical_list: D045424:Complex Mixtures; D008055:Lipids
keywords: Confocal fluorescence microscopy; Domains; Giant unilamellar vesicles; Lipid heterogeneity; Membranes; Rafts