Viral Safety Assays
Charles River offers a portfolio of in vivo, in vitro, and biochemical viral safety assays. Assays can be chosen and customized to address your specific concerns and needs, ensuring that an appropriate testing plan is designed for your product. Fast Track Testing is also available for quick delivery of urgently needed results.
In Vivo Assays
All testing is GMP compliant and testing protocols are designed to meet various regulatory requirements.
- Mouse, hamster, and rat antibody production (MAP, HAP, RAP) test.
- Adventitious virus assays, including specific assays for the testing of vaccines.
Cell-Based In Vitro Adventitious Agent Testing Assays
14- and 28-day adventitious agent assays
Our 14- and 28-day adventitious agent assays allow for the detection of low-level viral contaminants in biologics. We have a wide range of cell line and virus combinations available for use based on the nature of your sample.
Porcine and bovine adventitious agent assays
Our porcine and bovine adventitious agent assays follow for 9 CFR compliant detection of viral agents in fetal bovine serum, porcine trypsin, porcine pepsin, cell-free supernatants, cell lysates, and other bovine and porcine products.
Retrovirus detection assays
Our assays are designed to detect certain helper-type viruses including amphotropic and xenotropic murine leukemia viruses. Samples may first be amplified in susceptible cells and are detected with an S+L- focus assay.
XC plaque assay
Our assays for extended and direct XC plaque assays allow for the quantification of ecotropic murine leukemia viruses.
S+L- focus assay
S+L- assays are available for either direct detection or as an endpoint for other assays to allow for the detection of retroviruses.
EM analysis is performed by our Pathology Associated division and is GLP compliant. We offer both transmission and scanning electron microscopy. Ultrastructural morphology procedures allow for the visualization of unique structural details and quantification of cell organelles and subcellular structures. Additionally, we offer high throughput quantification of empty and full capsids in viral vectors and viral particle quantification. Review additional information about our TEM services.
Co-cultivation assays (murine, ecotropic, amphotropic, and rodent)
Our assays co-cultivate test cells with susceptible substrate cells for the isolation and amplification of potential infectious retrovirus that would otherwise not be detected by direct infectivity studies. A variety of endpoint assays, including PBRT, immunofluorescent staining, and S+L- focus assays, are available for detection.
Customized assays addressing specific contamination risks
Please contact us to address your specific contamination risks and discuss how we may develop appropriate assays.
Gene Therapy Vector Assays
Replication-competent virus: Adenovirus detection assay
Replication-Competent Adenovirus (RCA) may be generated in viral vectors as part of the production process. Our assay relies on amplification of potential RCAs in a susceptible, non-complementing cell line, followed by observation of adenoviral-associated cytopathic effect.
Replication-competent virus: Adenoassociated virus detection assay
Replication-competent adeno-associated viruses may be generated in viral vectors as part of the production process. Our assay relies on amplification of potential rcAAVs in a susceptible cell line co-infected with a helper virus. rcAAV is detected with a QF-PCR endpoint assay.
Replication-competent virus: Lentivirus detection assay
Replication-competent lentiviruses may be generated in viral vectors as part of the production process. Our assay relies on amplification of potential RCLs in a susceptible human T cell line. Amplified samples are subsequently added to fresh cells for detection. Endpoint testing is performed via ELISA and PBRT.
Adeno-associated virus infectious titers by TCID50 assay with QF-PCR endpoint
Infectious titers of adeno-associated viral vectors are performed on HeLa RC32 cells with a gene of interest specific QF-PCR endpoint. Infectious titers of adeno-associated viruses can also be determined on susceptible cells with a QF-PCR endpoint.
Quantification of viral vector genomic titers by ddPCR
Droplet Digital PCR is a technique that provides a higher degree of precision compared to QF-PCR, without the need for a standard curve or for a high degree of amplification efficiency. We have assays available to perform genomic titers of adeno-associated viruses and adeno-associated viral vectors. We also have experience creating assays for other viral vector targets.
Species-Specific Viral PCR Assays
- Standard QF-PCR and ddPCR based methods for detection and quantification of RNA and DNA viruses Method development available for customized assays.
- Rapid, sensitive, and specific broad-range PCR assays for adenoviruses, herpesviruses, papillomaviruses, and polyomaviruses.
- Detection of infectious retroviruses using PCR-based reverse transcriptase (PBRT) assay.
Frequently Asked Questions (FAQs) About Adventitious Agents
What are adventitious agents?
Adventitious agents are defined by the World Health Organization (WHO) as microorganisms that may have been unintentionally introduced into the manufacturing process of a biological medicinal product.
Why is adventitious agent testing important?
For any vaccine, medicine, or therapy produced using biological materials, there is the possibility that those materials may be contaminated with adventitious agents. If those adventitious agents are given to animals or humans, there is the risk that they could cause serious disease. In order to ensure the safety of biologics, regulatory agencies around the world have developed guidelines for adventitious agent testing to screen products for the presence of such adventitious agents.