Fig. 3. Specificity of R5BD-YFP and YFPEEA.1sh sensors for Rab5. (A) CFP-Rab4 was co-expressed with R5BD-YFP or YFP-EEA.1sh in PAE/EGFR cells. (B) CFP-Rab5 or CFPRab5(S34N) were co-expressed with YFPEEA.1sh in PAE/EGFR cells. YFP, CFP and FRET images were obtained from living cells at RT. FRETC images were calculated as described in Materials and Methods, and presented as pseudocolor images. A.l.u.f.i., arbitrary linear units of fluorescence intensity. Bars (A and B), 10 µm. (C) Gallery of high-magnification images shows individual endosomes or tethered endosomes in cells co-expressing CFPRab5(Q79L) and YFP-EEA.1sh or R5BD-YFP. FRET images are presented as pseudocolor intensity-modulated images (FRETC/CFP). Bar, 2 µm.