Related Experiment Video
Updated: May 5, 2026

Time-Resolved Fluorescence Anisotropy from Single Molecules for Characterizing Local Flexibility in Biomolecules
Published on: April 25, 2025
Fluorescence intensity and anisotropy decay of the 4',6-diamidino-2-phenylindole-DNA complex resulting from
1Center of Fluorescence Spectroscopy, Department of Biological Chemistry, University of Maryland, School of Medicine, 660 West Redwood Street, 21201, Baltimore, Maryland.
Abstract:
We examined the emission spectra, intensity decays, and anisotropy decays of the DNA-4',6-diamidino-2-phenylindole (DAPI) complex resulting from one- and two-photon excitation of fluorescence. Similar lifetimes and correlation times were recovered from the frequency-domain data. However, the initial anisotropies of DAPI for one- and two-photon excitation revealed different angles between the absorption and the emission oscillators, 17.8 and 23.8°, respectively. This suggests the presence of two overlapping transitions in DAPI with different one- and two-photon cross sections for absorption.
Related Concept Videos
Variables Affecting Phosphorescence and Fluorescence
Protein Dynamics in Living Cells
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...
Fluorescence and Phosphorescence: Instrumentation
Photoluminescence: Fluorescence and Phosphorescence
A pair of electrons in a...

