{"data":{"id":49,"name":"Fluorescence Correlation Spectroscopy","abbreviation":"FCS","description":"<p>Fluorescence Correlation Spectroscopy (FCS) is a highly sensitive technique for quantifying molecular dynamics by analyzing fluorescence intensity fluctuations as molecules diffuse through a tightly focused excitation volume. Using confocal detection, FCS correlates temporal fluctuations to extract diffusion coefficients, hydrodynamic radius, local concentration, and molecular interactions in vitro or in vivo. Its temporal resolution spans nanoseconds to seconds, enabling precise observation of fast biomolecular processes at the single-molecule level. Modern variants\u2014including dual-color FCCS, scanning FCS, pCF, and SPIM-FCS\u2014extend its capabilities to map spatial heterogeneity, detect interactions, and overcome photobleaching or cellular motion challenges.<\/p><p><\/p><p><img src=\"https:\/\/admin.molmedb.upol.cz\/storage\/uploads\/methods\/attachments\/6coJpbTTTsDyAoVBWCYRAIjXkc3l3mBVe9KHhRHu.png\" data-id=\"uploads\/methods\/attachments\/6coJpbTTTsDyAoVBWCYRAIjXkc3l3mBVe9KHhRHu.png\"><\/p><p>Principle, instrumentation, and data analysis of FCS. (<strong>A<\/strong>) schematic view, (<strong>B<\/strong>) the intensity trace, (<strong>C<\/strong>) The autocorrelation curve<\/p><p>Source of image: <a href=\"https:\/\/doi.org\/10.3389\/fphy.2021.644450\" class=\"ArticleLayoutHeader__info__doi\">10.3389\/fphy.2021.644450<\/a> (2nd July 2026)<\/p>","categories":[{"id":167,"title":"Positioning","breadcrumb":[{"id":4,"title":"Experimental"},{"id":167,"title":"Positioning"}]}],"url":"https:\/\/molmedb.upol.cz\/api\/v1\/methods\/49","landing_page":"https:\/\/molmedb.upol.cz\/method\/49","created_at":"2019-05-20T17:03:56.000000Z","updated_at":"2026-07-02T12:09:03.000000Z"}}