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Updated: Aug 7, 2026
Spot Variation Fluorescence Correlation Spectroscopy for Analysis of Molecular Diffusion at the Plasma Membrane of Living Cells
Published on: November 12, 2020
A theoretical method to analyze diffusion of probe molecules in nanostructured fluids by fluorescence correlation
Kazuhiko Seki1, Akiko Masuda, Kiminori Ushida
1National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 5, Higashi 1-1-1, Tsukuba, Ibaraki, Japan, 305-8565.
Abstract:
In this paper, we study the fluorescence fluctuation correlation function in structured fluids where the diffusion coefficients of probe molecules have different values depending on the distance from initial position, and we derive two simple expressions. Both of them reproduce the exact numerical results rather accurately. One of the expressions contains a time-dependent diffusion coefficient and has a clear physical meaning. We show a procedure to analyze experimental data using the time-dependent diffusion coefficient which results from crossover from free diffusion inside a mesh to hindered diffusion through mesh structures.
