Quenching + FRET

(2) Static QuenchingIn some cases, the fluorophore can form astable complex with another molecule. Ifthis ground-state is non-fluorescent thenwe say that the fluorophore has beenstatically quenched.In such a case, the dependence of thefluorescence as a function of thequencher concentration follows therelation:F 0 /F = 1 + K a [Q]where K ais the association constant of the complex. Such cases of quenching viacomplex formation were first described by Gregorio Weber.Static quenching:Ground-state fluorophore(fluorescent)nonfluorescent quencherQuencher-fluorophore ground-statecomplex (non-fluorescent)Static quenching only affectsthe complexed fluorophores.The properties of theuncomplexed fluorophoresare not changed.