I have a really old construct that contains GFP (original) tagged protein under CMV promoter. I can't find an empty vector containing GFP (Addgene or similar). The closest they have is eGFP under CMV promoter. Is it okay to use the latter as an empty control. I am not planning to quantify the intensity of green channel, green signal is only used to show transfected cells, so I am assuming the difference in the excitation/emission of GFP and eGFP is not going to affect my experiments. My only concern is the difference in cytotoxicity. Thanks.