Aedes aegypti is a major transmission vector for several arthropod-borne viruses (arboviruses), and with global warming and rising insecticide resistance, the increasing prevalence of this mosquito poses a threat to global health. Therefore, it is essential to develop new approaches to limit arbovirus transmission. One such possibility is modifying vector immunity to produce transgenic mosquitoes that limit transmission by suppressing arboviral replication. Antiviral immune responses of mosquitoes include the RNA interference (RNAi) pathway, and NF-κB-regulated Toll and immunodeficiency (Imd) pathways. Our work aims to develop stable cell lines that facilitate studies into arbovirus-vector interactions based on the A. aegypti-derived Aag2-AF5 cell line. These stable cell lines will help us investigate the function of the flavivirus non-structural protein 4A (NS4A) as an immune antagonist. We previously observed that the dengue virus serotype 2 (DENV-2) NS4A protein inhibits the activation of the Imd pathway from exogenous stimulation. However, these findings were limited because the transient transfection efficiency of Aag2-AF5 cells was only approximately 40%. We show that by generating stable cell lines using zeocin selection, the proportion of protein-expressing cells can be improved to over 90%. Using fluorescence microscopy, we monitored the stability of a control stable cell line expressing GFP over several passages once zeocin selection was removed. Overall, our work on flavivirus NS4A and the ability to generate stable cell lines will help improve our understanding of the underlying molecular virus-vector interactions that influence arbovirus transmission. Ultimately, our work takes the first steps towards generating mosquitoes that reduce arbovirus transmission.