Enhanced green fluorescent protein (eGFP) is a modified (F64L and S65T mutations) version of the native GFP protein isolated from jellyfish (Aequorea victoria), displaying increased fluorescence and more efficient folding. Enhanced GFP Lentiviruses (Inducible TET On) are replication incompetent, HIV-based, VSV-G pseudotyped lentiviral particles that are ready to infect almost all types of mammalian cells, including primary and non-dividing cells. These viruses constitutively express eGFP under a tight TRE tetracycline-inducible promoter . After induction with Doxycycline, eGFP expression can easily be visualized and optimized via fluorescence microscopy or flow cytometry. eGFP has an excitation wavelength of 488 nm, an emission wavelength of 509 nm, and extinction coefficient of 55,000 M^-1cm^-1.