Fluorescence Correlation Spectroscopy
The FCS facility at Scilifelab helps reserach groups to analyze biomolecular interactions in solution or in cells. The facility uses an FCS-equipped laser scanning microscope (Zeiss, model 780), but has access also to home-built instruments with the latest variants of FCS and FCCS including STED-FCS, FRET-FCS, RICS, Inverse FCS, SICS, and TRAST.
Even more important than the equipment is the experience of the FCS facility staff, who has used and developed FCS and related fluorescence techniques for more than 18 years, including several novel FCS variants.
Classic FCS analyzes biomolecules such as ligands diffusing through a femtoliter detection focus. Prolonged transit times through the focus indicate that the labeled ligands are interacting with receptors.
- FCCS detects the correlated movement of two binding partners labeled with different colour dyes, eg red an green. In contrast to FCS, no size-difference between binding partners is required.
- FRET-FCS can detect and quantify small FRET-active oligomers, even when present at only a few percent compared to monomers.
- STED-FCS can for example detect transient trapping of diffusing lipids on cell surfaces.
- Inverse FCS can measure the absolute size of domains on surfaces, down to 20 nm diameter using a confocal microscope and likely at least below 10 nm using a STED microscope.
- SICS can detect unlabeled and labeled nanoparticles simultaneously, and potentially biomolecules.
- Analysis and interpretation of experimental data.
- Project planning and experimental design of FCS-measurements.
- Support in specimen preparation.
- Training in FCS-techniques.