Adeno-associated virus (AAV) remains a leading viral vector candidate for gene delivery. However, the standard production of AAV makes use of ampicillin containing materials which can increase the risk of unwanted beta-lactam reactions in some sensitive patients. Researchers at Nationwide Children's have developed a novel plasmid, namely pHELP-kanV4, to replace the standard plasmid and allows for the production of recombinant AAV vectors without the chance of ampicillin gene or protein being retained as a contaminant in the final product. As a result, this will help increase the production of AAV for sensitive patients and especially in Europe where they is a strict guidance in the making of AAV.