AAVs are able to safely and efficiently deliver genes to mammalian cells and are thus at the forefront of academic research and therapeutic applications. AAVs expressing fluorescent proteins, such as GFP, provide a powerful imaging biomarker for AAV transduction. Different AAV serotypes exhibit different cellular tropism, many of which have yet to be characterized.
CFT technology is capable of determining tissue specificity of AAV serotypes across entire animals by imaging AAV mediated fluorescence in 3D. For example, 4 weeks following IV administration of AAV9-GFP, specific GFP signal is detected across the entire liver, as viewed in VivoQuantTM- generated MIP on the right side. Further confirming liver-specific fluorescence is the co-localization of GFP fluorescence to the liver imaged in the white light (asterisk). Control animal administered with PBS demonstrate only GI autofluorescence. This experiment provides high-resolution confirmation to the liver specificity of the tested AAV, that is only available using CFT. The use of GFP, together with the section collection capabilities, allow for down-stream processing, such as immunostaining and microscopy to further validate the cellular tropism of each serotype.
Animals were administered with AAV9-CAG-GFP (AAV9) and PBS (control) and allowed 4 hours of incubation. Animals were positioned in a prone orientation for image collection in white light and fluorescence. Images were processed in VivoQuantTM and fly-throughs of the data were generated for evaluation.