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Updated: Sep 23, 2026

Sensitive Detection of Proteopathic Seeding Activity with FRET Flow Cytometry
Published on: December 8, 2015
Demonstration of FRET in solutions
Sunil Shah1, Zygmunt Gryczynski1,2, Rahul Chib1
1Department of Cell Biology, Microbiology and Immunology, Center for Fluorescence Technologies and Nanomedicine, UNT Health Science Center, Fort Worth, TX 76107, USA.
Abstract:
We measured the Förster resonance energy transfer (FRET) from Uranin (U) donor to Rhodamine 101 (R101) acceptor in propylene glycol. Steady-state fluorescence measurements show a significant difference between mixed and unmixed fluorophore solutions. In the solution with mixed fluorophores, fluorescence intensity of the U donor decreases and intensity of R101 fluorescence increases. This is visualized as a color change from green to orange. Fluorescence anisotropy of the mixture solution increases in the donor emission wavelength region and decreases in the acceptor emission wavelengths; which is consistent with FRET occurrence. Time-resolved (lifetime) measurements show a decrease of the U lifetime in the presence of R101 acceptor. In the intensity decay of R101 acceptor appears a negative component indicating excited state process. All these measurements prove the presence of FRET in U/R101 mixture fluorescence.
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