Analysis of Recombinant Adeno-Associated Virus (rAAV) Purity Using Silver-Stained SDS-PAGE.

AAV virions are built from three major capsid proteins, VP1, VP2, and VP3, at a ratio of 1:1:18. On a silver-stained SDS-polyacrylamide gel, VP1, VP2, and VP3 should be the only visible bands in a highly purified recombinant adeno-associated virus (rAAV) preparation, migrating at approximately 87, 73, and 62 kDa, respectively. This protocol describes how SDS-PAGE and silver staining can be used to determine the purity of an rAAV preparation. In addition, using a highly purified rAAV preparation whose particle titer is known, this assay can be used to derive a semiquantitative estimate of the particle concentration of a test vector.