Transgene Expression in Cultured Cells Using Unpurified Recombinant Adeno-Associated Viral Vectors

Recombinant adeno-associated viral vectors (rAAV) can achieve potent and durable transgene expression without integration in a broad range of tissue types, making them a popular choice for gene delivery in animal models and in clinical settings. In addition to therapeutic applications, rAAVs are a useful laboratory tool for delivering transgenes tailored to the researcher's experimental needs and scientific goals in cultured cells. Some examples include exogenous reporter genes, overexpression cassettes, RNA interference, and CRISPR-based tools, including those for genome-wide screens. rAAV transductions are less harmful to cells than electroporation or chemical transfection and do not require any special equipment or expensive reagents to produce. Crude lysates or conditioned media containing rAAVs can be added directly to cultured cells without further purification to transduce many cell types—an underappreciated feature of rAAVs. Here, we provide protocols for basic transgene cassette cloning and demonstrate how to produce and apply crude rAAV preparations to cultured cells. As proof of principle, we demonstrate the transduction of three cell types that have not yet been reported in rAAV applications: placental cells, myoblasts, and small intestinal organoids. We discuss appropriate uses for crude rAAV preparations, the limitations of rAAVs for gene delivery, and considerations for capsid choice. This protocol outlines a simple, low-cost, and effective method for researchers to achieve productive DNA delivery in cell culture using rAAV without the need for laborious titration and purification steps.