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Fluorescence Correlation Spectroscopy (FCS)

Structural Determination Techniques (DNA, RNA and Protein)

  1. Aladdin Pramanik1,
  2. Jerker Widengren2

Published Online: 15 SEP 2006

DOI: 10.1002/3527600906.mcb.200300170

Reviews in Cell Biology and Molecular Medicine

Reviews in Cell Biology and Molecular Medicine

How to Cite

Pramanik, A. and Widengren, J. 2006. Fluorescence Correlation Spectroscopy (FCS). Reviews in Cell Biology and Molecular Medicine. .

Author Information

  1. 1

    Karolinska Institute, Department of Biochemistry and Biophysics, Stockholm, Sweden

  2. 2

    Albanova University Center, Royal Institute of Technology, Department of Physics, Stockholm, Sweden

Publication History

  1. Published Online: 15 SEP 2006


In Fluorescence Correlation Spectroscopy (FCS), fluctuations of the fluorescence intensity of fluorophore-labeled molecules, excited by a sharply focused laser beam, are observed. Owing to high sensitivity, detection at the level of single molecules is possible. Thermodynamic fluctuations can thus be revealed, which would be difficult to detect at a macroscopic level. The technique can, in principle, offer information about any molecular dynamic process in the nanosecond time range and longer, manifesting itself as a change in fluorescence intensity without the need for any perturbation or synchronization of the system studied. The specific features of FCS make it a versatile tool for biomolecular studies, including determination of translational and rotational diffusion, concentration and density of molecules, chemical kinetics, and binding reactions. In this review, an overview of the theory and the typical experimental setup for FCS measurements will be given, along with some examples of how FCS can be used for molecular dynamic studies.


  • Fluorescence Correlation Spectroscopy (FCS);
  • Brownian Motion;
  • Single Molecule Detection;
  • Molecular Interactions;
  • Drug Screening