What organic dyes are commonly used as fluorescent probes in FRET?

Cyanine dyes are widely used organic dyes in FRET due to their bright fluorescence and photostability. A commonly used FRET pair is fluorescein (as the donor) and rhodamine (as the acceptor). Fluorescein absorbs light at specific wavelengths and emits fluorescence while rhodamine captures the emitted fluorescence from fluorescein and emits its own fluorescence at different wavelengths. Alexa Fluor dyes are popular fluorescent labels known for their brightness, photostability, and minimal photobleaching. Alexa Fluor 488 and Alexa Fluor 594 are commonly used as FRET pairs.