title: Quantitative imaging of molecular order in lipid membranes using two-photon fluorescence polarimetry.
abstract: We present a polarimetric two-photon microscopy technique to quantitatively image the local static molecular orientational behavior in lipid and cell membranes. This approach, based on a tunable excitation polarization state complemented by a polarized readout, is easily implementable and does not require hypotheses on the molecular angular distribution such as its mean orientation, which is a main limitation in traditional fluorescence anisotropy measurements. The method is applied to the investigation of the molecular angular distribution in giant unilamellar vesicles formed by liquid-ordered and liquid-disordered micro-domains, and in COS-7 cell membranes. The highest order contrast between ordered and disordered domains is obtained for dyes locating within the membrane acyl chains.
authors.affiliation: Institut Fresnel-MOSAIC Group, UMR 6133, Centre National de la Recherche Scientifique, Université Aix Marseille III, Domaine Universitaire St Jerome, Marseille, France.
authors.forename: Alicja
authors.initials: A
authors.lastname: Gasecka
authors.forename: Tsai-Jung
authors.initials: TJ
authors.lastname: Han
authors.forename: Cyril
authors.initials: C
authors.lastname: Favard
authors.forename: Bong Rae
authors.initials: BR
authors.lastname: Cho
authors.forename: Sophie
authors.initials: S
authors.lastname: Brasselet
mesh_terms: D000465:Algorithms; D000818:Animals; D019556:COS Cells; D002462:Cell Membrane / Q000737:chemistry; D002645:Chickens; D002522:Chlorocebus aethiops; D002784:Cholesterol / Q000737:chemistry; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods*; D008859:Microscopy, Polarization / Q000379:methods; D008962:Models, Theoretical; D010713:Phosphatidylcholines / Q000737:chemistry; D013109:Sphingomyelins / Q000737:chemistry; D053835:Unilamellar Liposomes / Q000737:chemistry
chemical_list: D010713:Phosphatidylcholines; D013109:Sphingomyelins; D053835:Unilamellar Liposomes; D002784:Cholesterol; C017251:1,2-oleoylphosphatidylcholine