I used EBFP that I recloned into retroviral vectors. It gave very bright (but not very stable under UV)
blue signal that was detectable by microscopy (infected or transfected cells, DAPI filters, CMV and SV40
promoters) or FACS (transfected cells, CMV promoter). I noticed that EBFP/EGFP double marked cells appear
to have a peculiar color, but I am still working on a reliable test (filter setup), to unambiguously tell
them from single infectants or transfectants: there is a great variability in the color and intensity of
My impression is that EBFP works, although not as well as EGFP. My concern about FRET would be that, due
to rapid BFP bleaching, efficiency of FRET may greatly depend on precise timing of UV irradiation.
U09577 at uic.edu