I have a vector encoding GFP under UbC promoter activity. It's arrested by a floxed STOP signal (SV40).
- When I used it to transfect cells in vitro, N2A with FuGENE, in combination with a CRE vector, CRE recombined the STOP and GFP was expressed AND detected by fluorescent microscopy.
- HOWEVER, the same vectors when electroporated in utero in living tissue don't work properly: GFP is expressed, because I can detect it by immunostaining BUT GFP IS NOT FLUORESCENT, since I cannot find it by confocal microscopy.
Anyone can help me with this? How is it possible??
THANKS FOR YOUR TIME!