I am performing a translation study in mammalian cell culture. My construct includes: universal promoter of the vector, leader sequence of my gene of interest (which has a meaning in a translation efficiency), EGFP and FLAG tag. Using antibodies against FLAg I am able to obtain band of fusion protein of expected size in western blot - therefore I concluded that translation takes place in my culture. But EGFP signal is absent, when cells are observed under the fluorescent microscope.
Any ideas why I am having this problem?