In vivo detection of RNA-binding protein interactions with cognate RNA sequences by fluorescence resonance energy transfer

Quantification of lifetimes using Cerulean instead of ECFP as a FRET donor. (A) Cerulean-hnH and MS2-EYFP were coexpressed with constructs containing different binding sites, and Cerulean fluorescence lifetime was measured for each construct. pRed-M4x served as a negative control. Cerulean fluorescence, lifetime heat-maps, and histograms of lifetime distributions are shown. (B) Quantification of lifetimes shown in A. Decrease of lifetimes indicates FRET between Cerulean and EYFP constructs. The average and SEM are shown (SDs are indicated in Table 1), and the number of assayed cells is indicated within the bars.