TR-FRET technology combines the advantages of time-resolved fluorescence (TRF) and fluorescence resonance energy transfer (FRET) technologies. FRET technology utilizes the energy transfer between the donor fluorophore and the acceptor fluorophore combined by two biomolecules to emit light at a specific wavelength. However, in the traditional FRET technology, the background fluorescence signal is easily affected by the sample components, such as buffers, proteins, compounds, and cell lysates, which affect the experimental sensitivity and increases the complexity of data analysis. TRF technology can utilize the very long emission half-life of the lanthanides in the rare earth elements, which can remove the background with a short half-life, thereby reducing analytical interference and improving data quality. TR-FRET technology can be used to monitor the formation of polyubiquitin chains by analyzing the ubiquitin combined with the lanthanide fluorophore and the receptor fluorophore to perform in-vitro ubiquitylation assay. Moreover, fluorophore-labeled ubiquitin combined with terbium-anti-epitope-tagged antibody can also be utilized for mono-ubiquitylation detection.
