title: Performance of fluorescence correlation spectroscopy for measuring diffusion and concentration.
abstract: Fluorescence correlation spectroscopy (FCS) has become an important tool for measuring diffusion, concentration, and molecular interactions of cellular components. The interpretation of FCS data critically depends on the measurement set-up. Here, we present a rigorous theory of FCS based on exact wave-optical calculations. Six of the most important optical and photophysical factors that influence FCS are studied: fluorescence anisotropy, cover-slide thickness, refractive index of the sample, laser-beam geometry, optical saturation, and pinhole adjustment. Our theoretical framework represents a general attempt to link all relevant parameters of the experimental set-up with the measured correlation function.
authors.affiliation: Institute for Biological Information Processing 1, Forschungszentrum Jülich, 52425 Jülich, Germany. j.enderlein@fz-juelich.de
authors.forename: Jörg
authors.initials: J
authors.lastname: Enderlein
authors.forename: Ingo
authors.initials: I
authors.lastname: Gregor
authors.forename: Digambara
authors.initials: D
authors.lastname: Patra
authors.forename: Thomas
authors.initials: T
authors.lastname: Dertinger
authors.forename: U Benjamin
authors.initials: UB
authors.lastname: Kaupp
mesh_terms: D004058:Diffusion; D008962:Models, Theoretical; D013050:Spectrometry, Fluorescence / Q000379:methods*