title: Model-free methods to study membrane environmental probes: a comparison of the spectral phasor and generalized polarization approaches.
abstract: In this note, we present a discussion of the advantages and scope of model-free analysis methods applied to the popular solvatochromic probe LAURDAN, which is widely used as an environmental probe to study dynamics and structure in membranes. In particular, we compare and contrast the generalized polarization approach with the spectral phasor approach. To illustrate our points we utilize several model membrane systems containing pure lipid phases and, in some cases, cholesterol or surfactants. We demonstrate that the spectral phasor method offers definitive advantages in the case of complex systems.
authors.affiliation: Área de Investigación Respiratoria, Departamento de Fisiopatología, Hospital de Medicina-Facultad de Medicina, Universidad de la República, Montevideo, Uruguay; Biochemistry and Proteomic Analytical Unit, Institut Pasteur of Montevideo, Montevideo, Uruguay.
authors.forename: Leonel
authors.initials: L
authors.lastname: Malacrida
authors.affiliation: Laboratory for Fluorescence Dynamics, Biomedical Engineering Department, University of California at Irvine, Irvine, CA 92697, USA.
authors.forename: Enrico
authors.initials: E
authors.lastname: Gratton
authors.affiliation: Department of Cell and Molecular Biology, University of Hawaii at Manoa, 651 Halo St., BSB222, Honolulu, HI 96813, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Jameson
keywords: LAURDAN; generalized polarization; lung surfactant; membrane biophysics; spectral phasor