Figure 3.

Density gradient fractionation of adeno-associated virus (AAV) particles. (a) AAV2-hFIX vectors [1 × 10¹⁰ vector genome (vg)] purified by the gen1-chromatography (gen1-Chr) or chromatography-gradient (chr-gr) methods were subjected to sodium dodecyl sulfate–polyacrylamide gel electrophoresis (10%) followed by silver staining. (b) AAV2-hFIX vector purified by the gen1-chromatography method was subjected to CsCl density gradient ultracentrifugation. Fractions (0.5 ml) collected from the bottom of the tube were analyzed for AAV capsid protein by enzyme-linked immunosorbent assay (shaded), vector genomes (squares), residual HEK 293 genomic DNA (crossouts), and residual total plasmid DNA (triangles) by quantitative PCR (Q-PCR). The density (diamonds) of individual fractions was determined by refractive index. Error bars show ±SD of triplicate Q-PCR determinations. hFIX, human factor IX.