Fluorescence intensity (incl. FRET)
Fluorescence is the emission of light by a molecule (called fluorophore) that has been excited by light with a shorter wavelength than the emitted one. Fluorescence intensity detection is the measurement of this emitted light. A fluorescence plate reader consists of a light source, an excitation filter or monochromator, an emission filter or monochromator and a detector, usually a photomultiplier tube (PMT). As a result of a wavelength-specific excitation (light selected by the excitation filter/monochromator), the fluorophore emits light that is separated from the excitation light by the emission filter/monochromator and is measured by the PMT.
Fluorescence intensity is not an absolute measurement and is usually quantified in Relative Fluorescence Units (RFU). Thanks to the vast development of different fluorophores over the last decades, fluorescence intensity has become one of the most popular detection modes for plate readers, with thousands of assays available for many different applications.
Common applications for fluorescence intensity are calcium flux, DNA quantification, gene expression, protein interaction via Fluorescence Resonance Energy Transfer (FRET), enzymatic activities and more.
- Dual Channel Kinetic assays for detecting ligand bias at GPCRs
- Using FRET-based Measurements of Protein Complexes to Determine Stoichiometry with the Job Plot
- CLARIOstar determines activity of a moss-produced human acid alpha-glucosidase (GAA) in a ﬂuorescence-based assay
- Monitoring intracellular calcium using fluorescent dyes in a mid-throughput assay
- Measurement of red fluorescent dyes for improved multiplexing capabilities and cellular assays on the CLARIOstar Plus