QVirus^TM Platform

Creative Biogene provides world-class packaging services for a variety of viral types using our QVirus^TM platform. Our custom viral services are highlighted by a consistent high titer and large delivery viral counts.

Our expertise in virology enables us an industry leader in supporting the development and GMP manufacture of viral vaccines, gene therapies and other virus-based technologies for clients all over the world.

Viral vectors have been widely used as gene delivery vehicles. Compared to the conventional transfection methods, transduction usually results in much higher gene delivery efficiency, sometimes almost 100%. These are especially useful for gene delivery into primary cells or stem cells which is recalcitrant to conventional transfection methodologies. However, construction of a viral vector is a laborious process, and most commercial services in this area have so far been either too expensive or not user-friendly. With years of experience, Creative Biogene has launched a powerful QVirus^TM Platform for Lentivirus, Retrovirus, Adeno-associated Virus (AAV), Adenoviruses, Retrovirus, Oncolytic virus, etc.

Working Principle

Viral Vector Construction

Multiple Viral Vectors

Virus Packaging

Virus Purification & Titration

Advantages

The Working Principle of Viral Plasmids

In order to produce viruses with alternate (non-virus-producing) genomes, naturally occurring viral genomes have been adapted into a plasmid-based technology, such that plasmids can be used to create viruses with specific genomes (Figure. 1A). That is to say, instead of a virus infecting a host and giving rise to more viruses, researchers can introduce plasmids to a host to generate virus. Moreover, these plasmids can be modified to give rise to viral genomes of choice (Figure. 1B). Therefore, through standard plasmid cloning, viruses can be engineered to harbor a lot of viral genomes, enabling researchers to direct genetic functions widely in cells. For instance, if there is a protein thought to be associated with better memory, plasmids can be used to create viruses which encode that protein. Then, those viruses can be used to deliver the "memory" gene to the brain in mice and see if they can better remember how to solve a maze.

Figure 1. Using viral plasmids to generate virus.

Our QVirus^TM Platform

From many years of groundbreaking work with virus vector design to the latest gene therapy technologies support, our QVirus^TM Platform offers a comprehensive portfolio of services for the efficient design, development, manufacturing and analytical testing of virus vector products. Our expertise in virology enables us an industry leader in supporting the development and GMP manufacture of viral vaccines, gene therapies and other virus-based technologies for clients all over the world.

Multiple Viral Vectors Available

There are various types of viruses which are commonly used for research, each of which exhibits different properties, and therefore, are suited for specific research goals. For instance, AAV is typically preferred for in vivo studies owing to its low immunogenicity. Different types of viruses also vary in the composition of their viral genomes, with some having an RNA genome while others have a DNA genome. Furthermore, some viruses function by permanently integrating into the host's genome while other viruses are temporary in the host. Our QVirus^TM Platform has developed a number of viruses, including lentivirus, AAV, adenovirus and retrovirus, etc.

The charateristics of different viruses as follows:

Virus	Genome	Virus Size (nm)	Cells Infected	Expression	Packaging Capacity	Immune Response	Target Cell Genome Integration
Lentivirus	RNA	80-130	Dividing/Non-dividing	Stable	<8 Kb	Low	Yes
Adenovirus	dsDNA	105	Dividing/Non-dividing	Transient	>8 Kb	High	No
AAV	dsDNA	18-26	Dividing/Non-dividing	Transient/Stable	~ 4.5 Kb	Very Low	Yes/No
Retrovirus	RNA	80-130	Dividing	Stable	<8 Kb	Moderate	Yes

Viral Vector Construction

Our QVirus^TM Platform offers a variety of optimized viral vectors for your applications. We can subclone your gene of interest into the viral vectors with custom choices of promoters, tags, fusions, and selectable markers under different regulatory elements.

Vector-backbones	Lentiviral vectors, AAV vectors, Adenoviral vectors, Retroviral vectors
Fluorescent Fusion	GFP, YFP, RFP, CFP
Functional Fusion	Fc(IgG), GST, MBP, SUMO, StreptAvidin, Protein A/G, Luciferase, HRP
Epitope Tag	His, HA, Flag, Myc, 3xFlag, AviTag
Selectable Marker	Puromycin, Neomycin, Hygromycin, Blasticidin, Bleomycin

Virus Packaging

Viral vectors are one of the most efficient methods of gene delivery to mammalian cells both in vitro and in vivo. Through years of experience with viral vectors, our QVirus^TM Platform has developed its own proprietary virus packaging systems and efficient protocols for the rapid generation of pseudoviral particles. The viral expression constructs packaged into pseudoviral particles can be transduced into cells with very high efficiency, approaching 100% in some cell types. Packaged viral constructs can be transduced into even the most difficult to transfect cells, such as primary, stem, and differentiated cells with high efficiency.

Our QVirus^TM Platform offers packaging services for the following virus types:

Virus Type	Scale	Application	Upper Limit of Viral Genome	Upper Limit of User’s DNA Fragment
Lentivirus	Medium/large/Ultra-purified	Cell culture/In vivo	9.2 kb	6.4 kb
Adenovirus	Medium/large/Ultra-purified	Cell culture/In vivo	38.7 kb	7.5 kb
AAV	Medium/large/Ultra-purified	Cell culture/In vivo	4.7 kb	4.2 kb
Retrovirus	Medium/large/Ultra-purified	Cell culture/In vivo	8 kb	5.5 kb

Virus Purification and Titration

The highly purified virus is a requirement for a lot of downstream applications since cellular debris and proteins derived from culture media in crude virus preparation can be toxic to target cells and can cause immunogenic reactions when used for in vivo injection. Using purified virus stocks also prevents pseudo-transduction, in which high levels of recombinant protein in the crude supernatant are passively transferred to target cells during infection.

With years of experience in research of virus, Creative Biogene is able to produce high purity and high titer virus that is suitable for both in vitro cell experiments and in vivo animal tests. Our QVirus^TM Platform can help you to remove cellular contaminants, including uncharacterized infection and transduction inhibitors, residual plasmid DNA, cellular and serum proteins, and highly immunogenic viral proteins, nucleic acids, and virus fragments.