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Updated: Aug 20, 2026

Fluorescence Lifetime Imaging of Molecular Rotors in Living Cells
Published on: February 9, 2012
Acridones and quinacridones: novel fluorophores for fluorescence lifetime studies
J Anthony Smith1, Richard M West, Malcolm Allen
1Amersham Biosciences, Amersham plc, The Maynard Centre, Forest Farm, Whitchurch, Cardiff CF14 7YT, United Kingdom. j.tony.smith@amersham.com
Abstract:
Two new families of fluorescent probe, acridones and quinacridones, whose fluorescence lifetime can be altered to produce a range of lifetimes from 3 ns to 25 ns are described. Both families of fluorophore have fluorescence lifetimes which are unaffected by pH in the range of 5 to 9 and show a marked resistance to photobleaching. The probes have been modified to allow them to be attached to biomolecules and the labelling of a neuropeptide (substance P) is described. The labelled peptides have the same fluorescence lifetime as the free fluorophore. Quinacridone, with an emission around 550 nm offers a long fluorescence lifetime, photostable alternative to fluorescein.
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