The FRET efficiency Ea of the different FRET pairs, measured via Sensitized Emission.

ahttp://www.microscopyu.com/tutorials/java/fluorescence/fpfret/index.html b Calculated based on the GFP, mKate2, and tagRFP spectra from www.evrogen.com. For formulas see reference [39,44]. The spectral overlap of GFP-tagRFP and GFP-mKate2 are very similar (Evrogen spectra), but the extinction coefficient εA of mKate2 is smaller than the εA of tagRFP (62,500 vs. 100,000 M-1 cm-1). Multiplying the spectral overlap J(λ) of GFP-tagRFP with 0.625 resulted in a calculated R0 of 5.31 for GFP-mKate2. The FRET efficiency Ea of the different FRET pairs, measured via Sensitized Emission.