Inverse-Fluorescence Correlation Spectroscopy: label-free analysis of biomolecules in solution.
by
Stefan Wennmalm(KTH)
→
Europe/Stockholm
122:026
122:026
Description
Inverse-Fluorescence Correlation Spectroscopy (iFCS) is a recently developed modification of standard FCS that allows analysis of particles and biomolecules in solution without labelling. The particles generate no signal; instead the signal is generated by a surrounding medium. Particles diffusing through the FCS-detection volume displace a fraction of the surrounding medium, causing transient dips in the signal. These can give information about the analyzed particles’ mobility and concentration. Also labelled particles can be analyzed, whereby their signal is cross-correlated with the signal from the surrounding medium (iFCCS). This allows direct estimation of the volume of the analyzed particles, or alternatively about the size of the detection volume, if the volume of the analyzed particles is known. Finally, iFCCS allows simultaneous analysis of labelled and unlabelled particles/biomolecules. Thus, in a sample containing unlabelled particles/proteins and fluorescently labelled, small ligands, the fraction of all particles/proteins that carry a labelled ligand can be determined.
