fluorophore

This tutorial explores how electrons in common fluorophores are excited from the ground state into higher electronic energy states, and the events that occur as these excited molecules relax by photon emission and other mechanisms to ultimately fall back into the ground-level energy state.

This educational site offers background information on fluorescence as well as various applications in which it can be used.

This image gallery contains thumbnails of over 30 of the most common cell lines, labeled with a variety of fluorophores using both traditional staining methods as well as immunofluorescence techniques.

ISCID Encyclopedia of Science and Philosophy:\r\nFRET(Fluorescence Resonance Energy Transfer) is a technique for measuring interactions between two proteins in vivo. In this technique, two different fluorescent molecules (fluorophores) are genetically fused the two proteins of interest. Regular (non-FRET) fluorescence occurs when a fluorescent molecule (fluorophore) absorbs electromagnetic energy of one wavelength (the excitation frequency) and re-emits that energy at a different wavelength (the emission frequency)

GFP is a fluorescent protein isolated from coelenterates. Its role is to transduce the blue chemiluminescence of the protein aequorin into green fluorescent light by energy transfer. The gene for GFP has been isolated and has become a useful tool for making chimeric proteins of GFP linked to other proteins where it functions as a fluorescent protein tag. As a noninvasive fluorescent marker in living cells, it allows for a wide range of applications where it may function as a cell lineage tracer, reporter of gene expression, or as a measure of protein-protein interactions.

These pages illustrate aspects of fluorescence spectroscopy that are useful for elucidating structural and dynamic properties of proteins. Fluorescent techniques can provide parameters consistent with crystallographic results. The various environments of the fluorophores of a folded protein and the unique stereochemistry of the polypeptide chain affect the fluorophores in many ways which can be used to characterize and to follow changes in the folded conformation in solution. Fluorescence-based techniques can give information about a protein's conformation, binding sites, solvent interactions, degree of flexibility, internal motions, rotational diffusion coefficient, and many other physicochemical parameters.