Comparison of FRET probes and static quenching
FRET Probe is a dynamic quenching mechanism that does not affect the probe’s absorption spectrum. Hybridization of the dual-labeled probe to its target or nuclease activity disrupts the reporter-quencher dimer, allowing the reporter to return to the state allowing fluorescence to occur. Static Quenching (contact, ground state) involves formation of a reporter-quencher dimer. The intramolecular dimer effectively decreases the concentration of the fluorescent reporter by creating a new, non-fluorescent reporter-quencher dimer with a unique absorption spectrum.
Comparison of FRET probes vs static quenching:
| Ground State Complex Static Quenching |
FRET Probes Dynamic Quencing
|
| Static quenching |
Type of dynamic quenching |
| Dexter mechanism Förster |
Coulomb mechanism |
| Short distance < 20Å |
Long distance 40-100Å |
| Depends on e-R |
Depends on 1/r6 |
| Very temperature dependent |
Not very temperature dependent |
| Fluorophore absorption spectrum distorted |
Fluorophore absorption spectrum unchanged |
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11/05/2013