title: Combined AFM and two-focus SFCS study of raft-exhibiting model membranes.
abstract: Dioleoylphosphatidylcholine/sphingomyelin/cholesterol (DOPC/SM/cholesterol) model membranes exhibit liquid-liquid phase separation and therefore provide a physical model for the putative liquid-ordered domains present in cells. Here we present a combination of atomic force microscopy (AFM) imaging, force measurements, confocal fluorescence imaging and two-focus scanning fluorescence correlation spectroscopy (two-focus SFCS) to obtain structural and dynamical information about this model membrane system. Partition coefficients and diffusion coefficients in the different phases were measured with two-focus SFCS for numerous fluorescent lipid analogues and proteins, while being directly related to the lateral organization of the membrane and its mechanical properties probed by AFM. Moreover we show how the combination of these different approaches is effective in reducing artifacts resulting from the use of a single technique.
authors.affiliation: Biotechnologisches Zentrum, Technical University of Dresden, Tatzberg 47-51, 01307 Dresden, Germany.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Chiantia
authors.forename: Jonas
authors.initials: J
authors.lastname: Ries
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Kahya
authors.forename: Petra
authors.initials: P
authors.lastname: Schwille
mesh_terms: D001703:Biophysics / Q000379:methods; D002627:Chemistry, Physical / Q000379:methods*; D002784:Cholesterol / Q000737:chemistry; D005456:Fluorescent Dyes / Q000494:pharmacology; D008051:Lipid Bilayers / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry; D021962:Membrane Microdomains / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods*; D018613:Microscopy, Confocal; D008956:Models, Chemical; D010713:Phosphatidylcholines / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000295:instrumentation / Q000379:methods*; D013109:Sphingomyelins / Q000737:chemistry; D013696:Temperature; D013997:Time Factors
chemical_list: D005456:Fluorescent Dyes; D008051:Lipid Bilayers; D008081:Liposomes; D010713:Phosphatidylcholines; D013109:Sphingomyelins; D002784:Cholesterol; C017251:1,2-oleoylphosphatidylcholine