title: Combining fluorescence lifetime and polarization microscopy to discriminate phase separated domains in giant unilamellar vesicles.
abstract: Using fluorescence lifetime microscopy we study the structure of lipid domains in giant unilamellar vesicles made from sphingomyelin, 1,2-dioleoyl-sn-glycero-3-phosphocholine, and cholesterol. Lifetimes and orientation of a derivative of the fluorescent probe DPH embedded in the membrane were measured for binary and ternary lipid mixtures incorporating up to 42 mol % of cholesterol. The results show that adding cholesterol always increases the lifetime of the probe studied. In addition, the analysis of the probe orientation indicates that cholesterol has little influence on the ordering of the sphingomyelin alkyl chains whereas it has a noticeable effect on the structure of the 1,2-dioleoyl-sn-glycero-3-phosphocholine chains. The measurements made on the orientation and lifetime of the probe show the structure of the membrane in its liquid ordered and liquid disordered domains.
authors.affiliation: Université Louis Pasteur, Institut Charles Sadron, CNRS UPR 022, Strasbourg, France. haluska@ics.u-strasbg.fr
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Haluska
authors.forename: André P
authors.initials: AP
authors.lastname: Schröder
authors.forename: Pascal
authors.initials: P
authors.lastname: Didier
authors.forename: Denis
authors.initials: D
authors.lastname: Heissler
authors.forename: Guy
authors.initials: G
authors.lastname: Duportail
authors.forename: Yves
authors.initials: Y
authors.lastname: Mély
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Marques
mesh_terms: D002784:Cholesterol / Q000737:chemistry; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000378:metabolism; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D021962:Membrane Microdomains / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008859:Microscopy, Polarization; D010713:Phosphatidylcholines / Q000737:chemistry; D017785:Photons; D013109:Sphingomyelins / Q000737:chemistry; D013997:Time Factors; D053835:Unilamellar Liposomes / Q000737:chemistry* / Q000378:metabolism
chemical_list: D005456:Fluorescent Dyes; D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D013109:Sphingomyelins; D053835:Unilamellar Liposomes; D002784:Cholesterol; C017251:1,2-oleoylphosphatidylcholine
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