Syn-jGCaMP7b AAV (Serotype 9)

Unlike wild-type viruses, the genome of recombinant AAV vectors does not undergo site-specific integration into host DNA, but remains episomal primarily in the nucleus of transduced cells, with low frequency of random integration events. To date, 12 different AAV serotypes and 108 isolates (serotypes) have been identified and classified. Since the capsids interact with different receptors on target cells and influence the transduction step after entry, AAV vectors with different capsids have different transduction capacities (i.e., cell tropism and transgene expression kinetics), and users can choose the most appropriate capsid to target target cells. Recently, a universal multi-serotype AAV receptor (AAVR) has been identified. Since the AAVR appears to be essential for AAV infection, serotype-specific coreceptors and other factors should explain the diverse tropism of AAV capsid variants. AAV vectors can be produced in high yields by transient triple transfection of mammalian cells, infection of packaging mammalian and insect cells, or other methods. The triple transfection method is one of the most commonly used methods for producing AAV vectors, especially in research, but also in clinical settings. It is based on co-transfection of permissive cells (usually HEK293 cells) with three plasmids: one plasmid contains the transgene of interest flanked by the AAV ITRs, a packaging plasmid contains the rep and cap genes, and a third plasmid encodes adenoviral helper genes.