G&P Biosciences provides virus-based gene expression services for your research in cell lines or model organisms. Our virus services are focused on the lentivirus system with the advanced self-inactivating features, ensuring superior safety and transduction. Lentivirus can integrate into the host genome independent of cell cycle, allowing stable gene expression in hard-to-transfect, dividing and non-dividing cells. Its transduction efficiency is close to 100%, making it ideal for both in vitro and in vivo gene delivery. Our services include the preparation of lentivector constructs for your target gene and the production of ready-to-use, high-titer viral particles.  We also offer comparable services with the traditional retrovirus and adeno-associated virus systems in addition to virus-based shRNA & miRNA delivery (for a comparison of different viral delivery systems, please visit our "Technical Support" for more details).

Custom Lentivector Construction

(Service Code: VS-001)

We offer a variety of optimized lentivectors for your applications. We can subclone your gene of interest into any lentivector with custom choices of promoters, fusions, tags, and selectable markers under different regulatory elements (see the feature list below). When co-transfected with our lentiviral packaging DNA mix, these lentivectors create high-titer, replication-incompetent viral particles, allowing efficient packaging, transduction, and stable integration of your gene of interest into the target cell’s genome. These lentivectors alone can also be used for transiently constitutive expression of your gene of interest.

*Packaging kit includes an optimized lentiviral packaging (LentiPAK) DNA mix, a control vector, & a transfection reagent for producing high titers and robust expression levels.

We have a collection of sequence-verified gene clones pre-made in our lentivector (pLTC) under a CMV promoter for constitutive expression in almost any mammalian cell line. They can be searched to retrieve your gene of interest by key word, gene/protein name, family, classification, disease association, and biological pathway (click here to search and retrieve your gene of interest).  If you cannot find your target gene in our list or need a different format or variant, we can genereate and subclone it into any lentivector of your choice as a custom service project: 

 Custom Lentivirus Production

(Service Code: VS-002)

We provide services for custom lentivirus production (packaging).  Pre-packaged, ready-to-use viral particles are most reliable gene delivery tools for wide range of cell types. They are easy to use, simply add to cultured cells, and you will be able to confirm the target gene's expression within 48-72 hours. To request the service, just provide us your lentiviral expression construct or select one from our pre-made lentiviral gene clone collection, we deliver to you the ready-to-use virus at high titer. Custom-made titer ranges from 10⁷ IFU (Infection Function Unit)/ml using our optimal LentiPAK packaging kit (see the data example below). Our viral particles are provided in a serum-free medium, compatible with both in vitro and in vivo delivery.

Our high titer lentiviral particles are produced using standardized and optimized procedure with our LentiPAK packaging kit.  A collection of pre-made lentiviral gene clones can be searched to retrieve your gene of interest (click here to search your gene of interest).  Custom-made lentiviral particles are immediately available for these pre-made gene clones, covering many gene categories, such as controls (e.g, GFP, luciferase, HRP, LacZ, vector alone), enzymes, cell surface receptors, secreted proteins, and transcription factors (e.g., iPSC-related c-Myc, Klf4, Oct4, Sox2). 

Bundled Service Package

One-Stop Shop Solution: Gene-To-Virus

(Service Code: VS-G2V)

We offer bundled lentiviral gene expression service, “Gene-to-Virus”, a one-stop shop solution with standardized workflow and turnaround time. Bundle discount is included when you order the target gene lentivector clone and viral particles custom made by G&P Biosciences at the same time. We can amplify your target gene from the template you provide or synthesize the gene with optimized codon sequence for expression. We can subclone your target gene into our lentivectors, and deliver high titer, ready-to-use viral particles to you with a short turnaround time.  You have the options with different promoters, fusions, tags, or selectable markers to choose from (see the list above).

To request this bundled service, simply provide us the DNA nucleotide or protein amino acid sequence for the target gene to be delivered, and indicate the lentivector to use. If the protein sequence entered, select the species for codon optimization, e.g., mammalian, bacterial, mouse, or human. Upon receipt of your request, our service team will contact you with the optimized sequence, detailed lentivector design, pricing, and timeline information tailored to your needs.

Data Example

The data example below shows the determination of titer of functional lentivirus in three days using fused-GFP as the marker.  Serial dilutions of crude lentiviral particles (ranging from 1:30 to 1:1000) were transduced into equal amounts of target cells at the density of 0.6x10⁶/ml (1 ml each in 12-well plate) in the presence of 6 μg/ml of polybrene. The GFP-expressing populations (% GFP+) were determined by flow cytometry and monitored by fluorescence microscope 3 days post transduction (see the images below).  The functional titers were calculated using % GFP+ numbers and the formula below, ranging from 1.3x10⁷ to 1.7x10⁷ IFU/ml (with an average titer of 1.5x10⁷ IFU/ml).

Our custom-made lentivirus titer ranges from 10⁷ IFU/ml for the crude version, which can be concentrated to over 10⁹ IFU/ml, if desired. Our lentivirus production process involves stringent quality control measures.  Our lentiviral system is safe to use with the adaptation of latest safety standards and self-inactivation features.  Our pre-made lentivirus gene clones and custom-made viral particles provide a reliable, versatile and effective tool for gene delivery.  The viral particles can be used for stably long-term constitutive expression, e.g., inducing pluripotent stem cells (iPSC), and generating transgenic model organisms.

Additional Retrovirus Services

Custom Lentiviral shRNA

(Service Code: VS-003)

We offer custom lentiviralshRNA services to deliver short hairpin RNA expression constructs into cells for suppressing specific gene expression via RNA interference (RNAi).  We can design shRNA sequences for the genes of your interest (or use your validated shRNAs), construct the lentiviralshRNA expression clones, and generate ready-to-use, high titer shRNAlentivirus particles.  Upon request, we also provide you the negative control shRNA (e.g., null-control lentiviral particles) for examining the effects of virus infection upon a given cell line and validating the specificity of any target RNA interference effects. 

Average turnaround time is 4-6 weeks.

Custom Lentiviral miRNA

(Service Code: VS-004)

We offer custom lentiviral microRNA services, including the construction of lentivectors and the production of ready-to-use viral particles for the precursor miRNA expression for you selected human or mouse miRNA listed in miRBase databse. We also provide custom lentiviral anit-miRNA (specific to the desired miRNA) expression services: construct anti-miRNA lentivectors and produce ready-to-use lentivirus for inhibit any miRNA listed in miRBase databse.  Upon request, we provide the negative controls of miRNA or anti-miRNA for examining the effects of virus infection upon a given cell line and validating the specificity of any target regulatory effects. 

Average turnaround time is 4-6 weeks.

Custom Retrovirus Delivery

(Service Code: VS-005)

Upon request, we offer custom retrovirus services using the traditional retroviral systems derived from murine leukemia virus (MLV) & stem cell visrus (MSV). Two different pseudotyping options are available for viral packaging: (a) VSV-G pseudotyped retrovirus, which readily infects almost any types of dividing cells; (b) murine ecotropic envelope glycoprotein pseudotyped retrovirus, which only transduces mouse and rat cells.  We can design and generate the retroviral gene, shRNA and miRNA expression constructs and produce high titer, ready-to-use viral particles tailored to your specific needs.

Average turnaround time is 4-6 weeks.

For details and pricing information, please contact us by email: This email address is being protected from spambots. You need JavaScript enabled to view it.

Custom Adeno-Associated Virus

(Service Code: VS-006)

Upon request, we offer adeno-associated virus (AAV) services. AAV has become an increasingly valuable tool for in vivo studies in animals and for gene therapy in humans. Unlike adenovirus, AAV is non-pathogenic and elicits little immune response. AAV can infect non-dividing (quiescent) cells and remain expression for a long time despite it is rarely integrated into the genome. We can subclone your gene, shRNA, or miRNA into AAV expression vectors. We can perform custom virus packaging for scalable production of serum free, antibiotic free AAV stocks for your transgenic expression. We can prepare AAV stocks according to your requirements with multiple serotype options to choose from.

Average turnaround time is 4-6 weeks.

For details and pricing information, please contact us by email: This email address is being protected from spambots. You need JavaScript enabled to view it.

Important Safety Information

With the safety features in place, our lentiviral/retroviral vectors and viral particles can be employed in standard Biosafety Level 2 tissue culture facilities and should be treated with the same level of caution as any other potentially infectious agent. Any investigator who purchases our lentiviral/retroviral products & services is responsible for following Biosafety Level 2 requirements on the handling of viral particles. For more information on Biosafety Level 2 agents and practices, please refer to NIH’s “Biosafety Considerations for Research with Lentiviral Vectors”.