The AAV capsid structure is made up of a mixture of three viral proteins (VP), named VP1, VP2, and VP3. There are a total of 60 monomer VP molecules per viral particle in a ratio of 5 VP1: 5 VP2: 50 VP3 (see ref. 4). An anti-AAV VP antibody capable of binding all three VP subunits is absorbed onto a microtiter plate. AAV VP present in the sample or standard binds to the antibodies adsorbed on the plate; a biotinylated anti-AAV VP polyclonal antibody is added and binds to the AAV VP captured by the first antibody. Following incubation and wash steps, a Streptavidin-Enzyme conjugate is added that binds to the anti-AAV VP polyclonal antibody. Unbound Streptavidin-Enzyme conjugate is removed during the wash steps, and substrate solution is added to the wells. A colored product is formed in proportion to the number of AAV viral particles present in the sample. The reaction is terminated by addition of Stop Solution and absorbance is measured at 450 nm. A standard curve is prepared from inactivated AAV standard and sample concentration is then determined.
QuickTiter™ AAV Titer ELISA Kit recognizes the following serotypes: AAV-1, AAV-2, AAV-3, AAV-5, AAV-6, AAV-8, AAV-9, AAV-10, AAV-DJ and AAV-DJ/8.
