Figure 4. Neutralizing antibodies to AAV2 capid using in vitro assay. Serum samples were collected from animals at four weeks after receiving different route of injections (IM: intramuscular; IV: intravitreal; SR: subretinal), as well as from naïve animals that have not been exposed to AAV vector previously. Each sample was serially diluted. Each serum sample from serial dilutions was incubated with AAV GFP virus before infecting HEK293 cells. The percentage of inhibition was calculated using no-serum AAV2-GFP as the reference. Abbreviations: intramuscular injection (IM); intravitreal injection (IV); subretinal injection (SR). Serum samples from 4 animals were used for each route of injection of the AAV vector.