(A) shows the scheme of the FRET biosensor. An importin beta-binding domain (IBB) is flanked with YFP at the N terminus and CFP at the C terminus. This biosensor increases its FRET signal when ...
3) thus preventing discrimination of CFP and photobleached YFP on the basis of their emission or excitation spectra. During photobleaching FRET experiments, any increase in the CFP channel could ...