Adeno-associated virus (AAV) was discovered in 1965, as a contaminant of adenovirus (Ad) preparations, hence the name. It is replication-defective, non-enveloped small viruses (20nm) with a genome of single stranded DNA, from the parvovirus family. As 80-90% of humans are sero-positive with AAV2, most people treated with AAVs are non-pathogenic. Recombinant AAVs can infect both dividing and non-dividing cells and persist in an extrachromosomal state without integrating into the genome of the host cell.

The advantages of AAV compared to other viral vectors
● Long-term gene expression. rAAV genomes do not integrate into the host cellular genome, it persist in the nucleus in episomal forms. As cells replicate and divide, these episome will be lost. However, It can be expressed continuously for more than 6 months in tissues where cell division is not vigorous.
● Strong diffusivity. Due to small size and higher titer, rAAV has much higher diffusivity than adenovirus and lentivirus. And AAV can cross the blood-brain barrier, it is an ideal tool for neuron and glial cell infection.
● Specific expression can be achieved. AAV has a wide variety of promoters and serotypes, This enables AAV to recognize and infect different organs and cells, which make AAV as the first choice for animal experiments.
● High safety. AAV has not been found to cause disease to humans, and it is the safest viral vector approved by the FDA in US that can be directly used in human for gene therapy.
● low immunogenicity: When AAV is used to infect muscle, brain, eye and many others with local high dose, it is not easy to cause immune response;
● High stability. rAAV virus can be stored for 1 week at 4°C, and it is resistant to some reagents such as chloroform.

Viral vector	AAV	LV	Ad
Genome	ssDNA	ssRNA (+)	dsDNA
Coat	Naked	Enveloped	Naked
Type	Non-integrating	Integrating	Non-integrating
Infection	Dividing and non-dividing cells	Dividing and non-dividing cells	Dividing and non-dividing cells
Packaging Capacity	4.9kb	6kb	7.5kb
Transgene expression	Potentially long-lasting	Long-lasting	Transient
Immune Response	Very Low	Low	High
Titer	Up to 1012-13v.g/ml	Up to 109TU/ml	Up to 1012pfu/ml
Expression abundance	High-level expression	Moderate to high level expression	High-level expression
Safety	No pathogenicity has been found yet, Has been approved by the EU and FDA, Used as a carrier for gene therapy drugs	No pathogenicity has been found yet, It has been used in CAR-T therapy in the human	May cause some coughing and runny nose

Virus serotypes

Serotype	Tropism
AAV1	Muscle, heart, CNS, RPE, lung, skeletal muscle
AAV2	In vitro, CNS, RPE, muscle, liver,CNS
AAV5	Lung, RPE, CNS, pancreas, adipose, liver
AAV6	Muscle, lung, heart
AAV8	Liver, muscle, RPE, CNS, adipose, pancreas
AAV-pan	Pancreas
AAV9	Lung, liver, muscle, heart, CNS, adipose, BBB
AAV.rh10	CNS, BBB, pleura
AAV-Rec2	Adipose
AAV.DJ	In vitro, liver, heart, kidney
AAV2/RETRO	Retro
AAV.PHP.S	DRG, heart, colon
AAV.PHP.B	BBB
AAV.PHP.eB	BBB

 
Tips:
● If you are not sure which serotype to choose, you can try AAV9 .
● If you use AAV for the first time, you can use the Rainbow Colors AAV for pre-experiment. By which you can compare the infection effects of different serotypes on the target tissue, and explore the best injection method, injection site, virus dosage, etc., thereby getting more ideal experimental results.

Rainbow Colors AAV
Rainbow Colors AAV is a set product that combines common serotypes suitable for different organizations.

Rainbow Colors AAV	Serotype	Volume
Eyes/other organs	1/2/5/6/8/9/DJ	10 μL/serotype
Nervous system	1/9/Retro/PHP. eB	10 μL/serotype
Liver/Kidney	2/8/9/DJ	100 μL/serotype
Heart/Vascular/Muscle	1/6/8/9	100 μL/serotype

*AAV1 is used for anterograde tracer.
AAV9 is used as anterograde tracer.
AAVRetro is used for retrograde tracer.
AAV PHP.eB is suitable for crossing the blood-brain barrier.

Tissue-specific promoters
BrainVTA offers various tissue-specific promoters. Listed below are the most commonly chosen promoters. Don' see the promoter of interest, Please inquire.

Selection of vectors
BrainVTA provides a variety of AAV vectors, which can manipulate coding and non-coding genes through overexpression, RNAi and other technologies, such as lncRNA, microRNA, and circRNA. For more details, please contact sales@brainvta.com.